OSAT Elementary Ed Part 2

A pH meter produces the following readings for pure distilled water: 6.9, 7.3, 6.5, 7.2, 7.0, 6.8, 7.0, 7.6, 7.5, and 7.1. This apparatus is apparently:

Accurate but not precise. The average of all the readings is 7.0, which is the correct reading for pure water. This meter is producing readings near the correct reading, but it is not producing readings that are consistently the same.

What does the map represent?

Most of the land along the Red River is experiencing a significant decrease in population. The Red River runs along the southern border of Oklahoma. With few exceptions, the counties bordering the river saw population declines of up to 20% during the period of 2000-2010.

Homewood elementary school is organizing a math fair and inviting other schools to participate. Each team of Homewood students will have 3 members, while each team of students from a visiting school will have 4 members. If the number of Homewood teams is represented by h, and the number of visiting teams is represented by v, which of the following equations represents the total number of participants, p?

p=3h+4v Each homewood team has 3 participants, so the total number of participants from Homewood elementary school equals 3 times the number of teams, or 3h. Each visiting team has 4 participants, so the total number of participants from visiting schools equals 4 times the number of teams, or 4v. The total number of participants in the math fair, p, equals the sum of 3h and 4v.

European colonization of present-day Pennsylvania in the late 17th century is most closely associated with:

The desire for religious freedom Pennsylvania is most closely associated with William Penn, a Quaker of the Society of Friends. Penn hoped to establish a colony where Quakers would be free to practice their religion. This colony offered religious tolerance toward many other religions as well; Dutch Mennonites and German Baptists were among those who came to Pennsylvania.

Which of the following expressions shows the sum of a/b+c/d where a and be are not equal to 0?

ad+bc/bd

A student uses the function table to plot the points on a coordinate plane. The student can correct the plot by:

interchanging the x- and y-coordinates

A two-digit number is chosen at random. What is the probability that the chosen number is a multiple of 7?

13/90 There are 90 two-digit numbers (all integers from, and including, 10 to, and including, 99). Of those, there are 13 multiples of 7: 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98.

Accurately describe how a technological innovation affected the outcome of a historical event?

*the development of radar gave Allied powers a crucial tool or defending themselves from Axis bombers during World War II. Although theories about radar were put forth during the lat 19th and early 20th centuries, radar technology was not seriously developed until the 1930's. During World ar II, allied nations such as Great Britain depends on radar to laert both soldiers and civilians to approve enemy bombers and used radar to guide search lights and aim antiaircraft weapons.

A student evaluated the expression 4+(6x7)/2-9 and got an answered of -2. Which of the following statements best describes the student's work?

*the student incorrectly performed subtraction before multiplication and division . According to the order of operations PEMDAS, operations in parentheses should be performed first, followed by multiplication and division, followed by addition and subtraction. In the expression 4+(6x7)/2-9, the first steps is to multiply, 6x7, resulting in 4 + 42/2-9. The next step is to divide 42/3, resulting in 4/21-9. Finally, add and subtract to get an answer of 16. This student however, subtracted 2-9 before dividing by 2, resulting in 4 + 42 (-7), which is -2.

What contributed most to the evolution of democratic government?

*the writings and ideas of Enlightenment philosophers. Major enlightenment philosophers included John Lock whose Two Treatises of government argued that people against the divine right of kinds, and Jean-Jacques Rousseau, whose the social contract argued that people form government to protect their liberty. Both works profour influenced the leaders of the American Revolution and the frames of the US Constitution.

Which of the following inequalities is equivalent to -50<-7x-1<6?

-1<x<7

The expression 83x10(-2) is equivalent to which of the following numbers?

0.083 A number with a negative exponent equals the reciprocal of that the number with a positive exponent. Therefor 10 (-2)=1/10(2)=1/100=0.01. Finally 8.3x0.01=0.083

A teacher is considering buying classroom supplies at either an office supply store or a general store. The price of the supplies at the office supply store is $98.20 but teacher receives a discount on all purchases. The price at the general store is $102.92, but the teacher has a coupon of $20 off a purchase of $100 or more. If the discount at the office supply store is applied, the teacher would spend $4.36 less at the office supply store than at the general store. What discount do teachers receive at the office supply store?

20% the supplies at the general store will cost $102.92-20=$82.92. That is $4.36 more than the cost would be at the office supply store so the supplies will cost $78.50 at the office supply store. Express the cost at the office supply store after the discount as a percentage of the cost before the discount 78.56/98.20x100%=80%. The cost after the discount is 80% of the cost before the discount, so the discount is 20%.

According to a 2012 study, about 20% of 5th graders in the US have a cell phone. If the digits 1 and 2 in the random number table represents 5th grade students who have a cell phone, what is the probability that in a group of 5 randomly selected 5th grade students, at least 2 students will have a cellphone?

28% If each digit in the table represents one 5th grade student, then each cell in the table represents a group of 5 randomly selected 5th grade students. Count the number of cells in which at least two of the five digits are 1's or 2's. There are 7 such cells out of a total of 25 cells, so the probability is 7 out of 25% or 28%.

If a is an odd, prime number, which of the following numbers could also prime?

2a a+ 1 -a a+4. *a+4 2a is not prime because it has 2 and a as factors. Negative integers are not prime because they have -1 as a factor. The sum of two odd numbers is an even number, and all even number, and all even numbers have 2 as a factor, so a+1 is not prime. However, for example, if a+13, then a + 4=17. Both13 and 17 are prime numbers,

A school principal is buying new rubber chips for the school playgrounds. One playground measures 30 feet by 50 feet and will require 18,000 pounds of rubber chips, Another playground measures 25 feet by 40 feet. If the second playground will be covered with the same depth of rubber chips as the first playground. What is the total number of pounds of rubber chips that will be needed to cover both playgrounds?

30,000 the first playground has an area of 30 feet x 50 feet=1,500 square feet and will require 18,000 pounds of rubber chips. The second playground is 25 feet x 40 feet=1,000 square feet and will require x pounds of chips. Set up the proportion 1,500/18,000= 1,000/x and solve for x Because x +12,000 the total pounds of chips needed to both playgrounds is 12,000 +18,000=30,000lbs

Which of the following examples best demonstrates the relationship between structure and function?

A bird that eats by cracking seeds and nuts has a shorter, thicker beak than a bird that eats by probing the ground for worms. Birds have many different kinds of beaks. The structure of a particular birds beak-whether it is long or short, thick or narrow, hooked or flat depends mainly on how it functions to help the bird located and consume food.

A student places ice cubes in a beaker and places the beaker on a hot plate. As the ice cubes are heated they melt, and the student measures the water's temperature at various times. Which of the following types of graphs will best display these data?

A line graph that plots time on the x-axis and temperature on the y-axis. A line graph is particularly effective for representing change over time. By plotting the independent variable (time) on the x-axis and the dependent variable (temperature) on the y-axis, the student can see where the water's temperature remains constant (flat lines) and where the water's temperature increases (curved lines).

Which of the following word problems can be solved by modeling with a linear function?

A linear function is a function that produces a straight line when graphed: as x changes, y changes at a constant rate. The total for an overdue book (y) can be represented by a linear function in which x equals the number of days late: y=$0.15x+ $3. The library charges a $3 fee for processing overdue books, as well as $0.15 per day per book. What is the fee for a book that is 25 days overdue?

A students research project would most benefit from a visit to the Pioneer Museum in Ponca City, Oklahoma to investigate frontier handicrafts.

A museum devoted to the experiences of pioneer women should have as a primary focus the domestic artifacts-furniture, clothing, cooking utensils, looms-that played a central role in the lives of women on the frontier.

In which of the following examples does an artist use negative space to achieve an effect?

A painter makes a figure seem small by surrounding it with white canvas. Negative space refers to the parts of a painting that surround the main objects. Often these parts are empty, and the contrast between an object and the negative space that surrounds it can influence how the viewer sees the object.

Given what scientists know about plate tectonics, which of the following locations on the ocean floor likely contains the youngest rocks?

A ridge alongside a rift valley. At a mid-ocean ridge, tectonic plates diverge, or move apart. Between the diverging plates, a rift valley forms where magma form Earth's interior rises and produces new rock as it cools. Thus, rock closer to mid-ocean ridges is typically younger than rock farther from mid-ocean ridges.

Which of the following scenarios best exemplifies the climax stage of the dramatic arc?

A runner in a championship race crosses the finish line in first place. The climax of a play is the moment of greatest tension, when the protagonist's fate is determined; it follows from the rising action and leads to the denouement or resolution. In a play about an athlete preparing for a major race, the climax would likely be the moment when the athlete crosses the finish line.

Amara, Bryan and Corrine have three identical solids made of wood. Amara cuts her solid so that the resulting cross section is a triangle. Bryan cuts his solid so that the resulting cross section is a trapezoid. Corrine cuts her solid so that the resulting cross section is a square. The original solid could be a:

A square pyramid has a square base and four triangular faces. A cut parallel to the base will produce a square cross section. A cut perpendicular to the base through the apex of the pyramid will produce a triangular cross section. A cut perpendicular to the base that is not through the apex of the pyramid will produce a trapezoid cross section. Answer: square pyramid

A tariff that is being imposed when the federal government places a tax on automobiles manufactured outside the country.

A tariff is a tax that a country imposes on foreign goods. A resident of the US who buys an automobile produced in another country must pay the cost charge by the manufacturer plus the tariff or tax imposed by the government.

Which of the following statements accurately describes an important interrelationship between human organ systems?

After the digestive system breaks down food into nutrients, the circulatory system transports nutrients to the cells of the body. The digestive system includes organs such as the stomach and the small and large intestines, which break down food by separating nutrients from waste products. Nutrients are then absorbed into the bloodstream and pumped throughout the body by the heart, which is the main organ of the circulatory system.

In which of the following ways are modern dance and jazz music similar?

Artists in both genres frequently perform without a predetermined score. An important characteristic of jazz is its improvisational quality. Often jazz musicians are encouraged to improvise rather than follow a set score. Similarly, many modern dance pieces feature improvisation, rather than follow a choreographed score, dancers allow music to shape their movements in the moment.

This is an example that accurately describes how a geologic process creates or affects landforms when a river deposits sediments.

As it flows to sea, it fertilizes the soil of a coastal plain. As rivers flow to sea they carry sediments that contain a variety of minerals. Where the rivers meet the ocean their rate of low often diminishes, allowing the sediments to be deposited in the form of nutrient rich coastal plains.

The scatter plot shows the average rainfall and number of days of rain in July for several cities. The relationship between the number of days of rain and total rainfall is best described as a:

As the number of days of rainfall increases, the total rainfall tends to increase, so, the association is positive. The data points are not clustered closely along a trend line, so the association is weak. Answer: weak, positive association.

A scientist studies a sample of matter that consists of three types of particles. Some particles have 6 protons and 6 neutrons, other particles have 6 protons and 7 neutrons, and particles of the third type have 6 protons and 8 neutrons. These observations suggest that the particles being observed are:

Atoms of the same element. Atoms of the same element have the same number of protons. This sample consists of 3 isotopes of carbon, an element whose atoms contain 6 protons each

Which of the following types of classification schemes is best described as hierarchical?

Biological classification of organisms The biological classification of organisms places different species in to a hierarchical system of categories based on shared characteristics and evolutionary relationships. The system is hierarchical because each category that is higher up in the system is broader and more inclusive. A particular species at the lowest level o the system is described using a binomial naming scheme that includes the larger genus category that the organism belongs to and its species name.

Which of the following statements accurately explains how playing a sport can improve a student's motor skills?

By playing modified basketball, a child practices locomotor skills, such as jumping, and manipulative skills, such as dribbling a ball. Fundamental motor skills include locomotor, nonlocomotor, manipulative, and body control skills. Students develop locomotor skills while traveling and moving their bodies from one place to another, including away from the ground; hence, jumping is a locomotor skill, along with skills such as walking, running, and hopping. Students develop manipulative skills by learning to control objects such as balls with their hands, feet or implements. Dribbling is a manipulative skill, along with skills such as throwing, catching, kicking, and trapping.

Which of the following statements best describes the point of view expressed in the cartoon above?

Destructive weather has caused tremendous human suffering in the Midwest. This cartoon shows a tornado ripping through "America's Heartland," a common term of the midwestern region of the United States. The image of a heart "breaking suggests the human suffering caused by destructive weather in the region.

Which of the following is an example of safe behavior during a science investigation?

Diluting a concentrated acid by adding it to a beaker of water. Adding water to concentrated acid will generate heart than can cause splattering. Adding acid to water will generate less heat and therefore is less of a risk to splatter.

On a hot afternoon, a person on a beach feels a breeze blowing off the ocean. At night, however, a breeze blows off the land toward the ocean. Which of the following statements best explains these observations?

During the day the air above the beach heats more quickly and rises, allowing cooler air from above the ocean to flow beneath it; at night, the air above the beach cools more quickly, sinks, and flows beneath the warmer air above the ocean. The person is observing sea breezes and land breezes. Because water has a greater heat capacity than land has, water heats more slowly during the day and cools more slowly at night. As a result, the air above water also heats and cools more slowly. Because warm air rises and cool air sinks, cooler air flows from the ocean to the beach during the day (sea breeze) and form the beach to the ocean at night (land breeze).

The constitutional principles that was most advanced by the 19th century movement to abolish slavery in the US was

Equal protection under the law. The success of the abolitionist movement resulted in constitutional amendments that outlawed slavery and protected the legal rights of people in the US. Per the 14th amendment "No state shall make or enforce any law which shall abridge the privileges or immunities of citizens of the US; nor shall any State deprive any person of life, liberty or property, without due process of law, nor deny to any person within its jurisdiction the equal protection of the laws".

A substance evaporates. Compared to the molecules in the original substance, the molecules in the resulting substance:

Have more energy and travel greater distances. Evaporation is the changing of a liquid to gas. A substance typically evaporates when it is heated, so its molecules have more energy, which allows them to travel greater distances.

Two complex numbers a + ib and c + id are identical

If and only if a = b and c= d For two complex numbers to be identically equivalent, both the real coefficients (a and c) and the imaginary coefficients (b and d) must be identically equivalent to each other, respectively.

The students at Sunnyside Elementary School went on a field trip to the science museum. There was 1 adult on the trip for every 10 students. The admission fee was $5 per person. Three buses were necessary to transport everyone to the museum, and the bus company charged $95 per bus. The total cost of admission and transportation was $945. Which equation can be used to find the number of students, s, on the field trip?

If, s, represents the number of students, there were ,0.1s, adults on the trip and the total number of people on the trip was s+ 0.1s. Each person paid $5 to ender the museum, so the total cost of admission was 5(s+0.1s). The total transportation cost was the product of the number of buses 3, and the cost per bus, $95. So, the total cost of admission and transportation was 5(s+0.1s) +3(95), which equals the total cost of the trip; $945.

This could happen in a democracy but not in a republic where everyone lives in a society that gathers to propose and vote on new laws.

In a democracy, the power to enact laws rests directly with the people. In a republic the people elect representatives who legislate on the people's behalf.

Test scores for a Spanish exam were recorded in two different ways, using the graphs shown. Both graphs can be used to:

In a stem-and-leaf plot, each numver in the leaf column represents one piece of data. Counting the numbers in the leaf column gives the total number of test scores, 18. In the histogram, each bar represents the number of scores in a range, shown on the horizontal axis. Adding the frequency values for each bar, 1+2+3+6+4+2=18, will find the total number of test scores. Answer: find the total number of test scores.

Friends and Fellow-citizens: I stand before you tonight, under indictment alleged crime of having voted at the last Presidential election, without having a lawful right to vote. It shall be my work this evening to prove to you that in thus voting, I not only committed no crime, but instead, simply exercised my citizen's right, guaranteed to me and all Unit States citizens by the National Constitution, beyond the power of any State to deny. The preamble of the Federal Constitution says: "We the people of the Unites States, in order to form a more perfect union, establish justice, insure domestic tranquility, provide for common defense promote the general welfare, and secure the blessing of liberty to ourselves our posterity, do ordain and establish this Constitution for the United States America." It was we, the people; not we, the white male citizens; nor yet we, the male citizens; but we, the whole people, who formed the Union. The only question left to be settled now, is: Are women persons? And I hardly believe any of our opponents will have the hardihood to say that they are not. Being persons, then, women are citizens, and no state has a right to make any new law, or to enforce any old law, that shall abridge their privileges or immunities. Hence, every discrimination against women in the constitutions and laws of the several states, is today null and void.

In her speech, Anthony's most central claim is that: Laws that discriminate against women are unconstitutional. She argued that the U.S. Constitution enjoins states from denying or restricting rights granted to citizens under the constitution or treating one group of citizens differently from another group. Given that state have the constitutional responsibility for holding elections, yet that under state law women were not allowed to vote in those elections, such laws were by definition unconstitutional.

Show Boat (1927) and Oklahoma! (1943) were influential American musicals primarily because they

Integrated dialogue, music, and dance to tell coherent stories. Prior to Show Boat, works of musical theatre were essentially revues with thinly developed characters and plots; singing and dancing often interrupted rather than furthered the story. Historians generally consider Show Boat to be the first work of musical theater that blended music, dance, and dialogue into a unified whole, with complex characters and a serious plot. Oklahoma! further developed these elements.

Which of the following experiments will produce the most valid data?

Investigating the effects of forces on motion by rolling marbles down a ramp; for each trial, students change the height of the ramp and measure the distance the marble travels. A good experimental design identifies one independent variable and one dependent variable; the scientist manipulates the independent variable and measures the effects on the dependent variable In this investigation, the height of the ramp is the independent variable and the distance the marble travels is the dependent variable. Such an experiment will likely produce valid data.

Which of the following examples accurately describes how Galileo Galillei influenced another scientist?

Isaac Newton used Galileo's studies of inertia to develop physical laws of motion. As Galileo studied moving objects, he observed that balls rolled farther along smoother surfaces. He theorized that a perfectly smooth ball would roll forever, without stopping, along a perfectly smooth, level surface. Newton incorporated these ideas into his first law of motion, sometimes called the law of inertia, which partly states that an object in motion stays in motion unless acted on by an unbalanced forces such as friction.

Which of the following features of collage makes it a particularly appropriate type of artwork for elementary students?

It is often made from inexpensive, found materials. Collage is a technique in which an artist creates an image by combining various everyday materials for example; bits of string, photographs, and words and letters cut from texts. Often, the artist simply glues these materials to a piece of paper or canvas. Consequently, collage is a relatively inexpensive and accessible way to make art.

How did the Truman Doctrine shape U.S. foreign policy after World War II?

It led to U.S. military involvement in countries such as Korea. The Truman Doctrine was intended to prevent Greece and Turkey from becoming communist countries. However, its broad language had implications beyond those two nations, suggesting that U.S. policy generally should be to aid people who resisted outside forces attempting to impose communist rule. The Doctrine led to U.S. involvement in Korea and Vietnam, where U.S. forces fought against communist forces in those nations.

Which statement best describes the significance of the Mayflower Compact on colonial America?

It provided the Pilgrims the first written basis for laws in the New World. The male passengers of the Mayflower signed the Compact after a disagreement regarding where in the Americas they should establish a colony. The Compact served as a written basis for laws in their subsequent colony.

The painting combines characteristics of which two pictorial genres?

Landscape and still life. In a still life, the artist arranges inanimate objects for aesthetic effect. In a landscape, the artist represents an outdoor scene. This painting combines characteristics of both genres; the painter arranges a collection of bottles, bowls, and pieces of fruit on the slope of a grassy hill.

A figure plotted on a coordinate plane has vertices P(8,4), Q(6,-1), R(-5,-1), and S(-3,4). Which of the following statements best describes PQRS

Rectangles are quadrilaterals with two pairs of congruent sides. Opposite sides are parallel, and intersecting sides are perpendicular. The slopes of perpendicular lines are negative reciprocals of each other. Quadrilateral PQRS has two pairs of congruent sides, but the slope of PQ is 2.5 and the slope of QR is 0. Therefore, PQRS is not a rectangle because the slopes of intersecting lines are not negative reciprocals of each other. Answer: PQRS is not a rectangle because the slopes of intersecting lines are not negative reciprocals of each other.

Quadrilateral ABCD is transformed to produce an image A'B'C'D'. Quadrilateral A'B'C'D is the transformed to produce image A"B"C"D". Quadrilateral A"B"C"D" is similar, but not congruent, to quadrilateral ABCD. Which of the following pairs of transformations could produce quadrilaterals A"B"C"D"?

Rotations, reflections, and transformation are rigid motions that produce images that are congruent to the pre-image. Dilations produce images that are similar to the pre-image with sides that are proportional to and angles that are congruent to the corresponding measures in the pre-image. Consecutive dilations by scale factors that are reciprocals of each other produce an image that is congruent to the pre-image. A transition followed by a dilation will produce an image that is similar, but not congruent, to the pre-image. Answer: vertical translation followed by the dilation by scale factor of 1.5.

A project that requires a 6th grade students to use secondary sources such as; Analyzing information about Civil War battle tactics and strategies, typically

Secondary sources include accounts and analyses of historical events created by people who did not directly experience the events. Information about tactics and strategies, typically compiled by historians from multiple military and personal records, in an example of the use of secondary sources.

Which of these approaches to mathematics instruction is generally recognized as being the most effective?

Students should be encouraged to solve problems in ways that make sense to them. Each student is a unique individual, and different students may have different ways of conceptualizing the same problem. In the long run, allowing students to find their own ways of thinking about mathematics will make them better problem solvers. Mental math has an important role to play in everyday life. Memorization and drills also have their place, but they should be the central focus in the classroom.

The teachers at Elm Grove Elementary School are planning a picnic for the 5th grade students. They want to survey some students to learn what types of outdoor activities to plan for the picnic. Which of the following sampling methods would provide the most reliable information about student preferences for activities at the picnic?

Surveying every 10th student to arrive one morning In order for the results of a survey to provide a reliable basis for drawing inferences about the population, the sample needs to be representative of the population. Surveying every tenth student to arrive at school will provide a random sample of students who will probably represent different grades and interests.

The Bill of Rights grants all U.S. Citizens the right to a public trial.

The Bill of Rights consists of the first 10 amendments to the US Constitution. Amendment VI grants those accused of crimes "the right to a speedy and public trial".

During a wellness unit, 5th grade students will form small groups and research disease-prevention strategies in the context of a particular type of disease. Which of the following resources is most likely to provide students with valid, reliable information for their research assignments?

The Web site of a national voluntary health organization, such as the American Cancer Society. National voluntary health organizations, such as the American Cancer Society, are considered reliable sources of accurate and current, and useful health-promotion and disease-prevention information. These nonprofit organizations typically support medical research into developing treatments and cures for disease and provide information on promising research, strategies for healthy lifestyles, approaches for preventing and managing disease, and methods of accessing support for individuals living with the disease.

New carpet is being installed in a classroom. The main part of the classroom is a rectangle that measures 29 feet by 21 feet. The classroom also includes a square alcove with 6-foot sides. Which of the following expressions can be used to find the total area of carpet needed for the classroom and alcove.

The amount of carpet equals the total area of the classroom. The classroom can be imagined as a larger rectangle that includes the alcove, with a rectangular part removed. The larger rectangle measures (29+6) by 21, and a rectangle measuring 6 by (21-6) must be subtracted. So the area of the rectangle can be expressed as (35)(21)-(6)(15). Answer is: (35)(21)-(6)(15)

A field is home to grasshoppers, mice and rabbits, all of which eat grass. The field also home to crows, which eat grasshoppers, and foxes, which eat mice and rabbits. If a disease kills off the foxes, then most likely:

The grass population would decrease. If the foxes die off, fewer mice and rabbits will be killed by predators. More mice and rabbits will eat more grass, causing the grass population in the field to decrease.

The US government and the state governments share this responsibility with the court system.

The judicial system of the United States includes both state and federal courts. Typically, state courts hear cases that involve state laws and constitutions. and federal courts hear cases that involve federal laws and the US Constitution, federal courts also hear cases that involve disputes between states.

An 8-foot ladder is leaning against wall of a building. The base of the ladder is 5 feet from the base of the wall. The building has a window, the bottom of which is 9 feet above the ground. Approximately how many feet below the bottom of the window does the top of the ladder rest?

The ladder is the hypotenuse of a right triangle whose legs are the distance form the wall to the base of the ladder, and the distance up the wall to the top of the ladder. Using the Pythagorean theorem, 5(2)+x(2)=8(2), where x is the distance up the wall to the top of the ladder. Solving for x, the ladder reachers 6.2 feet up the wall. This is 2.8 feet below the bottom of the window which is 9 feet above the ground. Answer : 2.8

What is a significant negative consequence of the construction of dams and the creation of artificial lakes?

The loss of species that cannot adapt to altered habitats. When a river is dammed, an artificial lake forms upstream of the dam while downstream the river may dry up completely. Organisms living on both sides of the dam may not be able to adapt to the sudden changes, forcing them to migrate to more habitable environments or perish.

A bag contains 6 red marbles, 5 blue marbles, 7 green marbles, and 2 yellow marbles. A student selects a marble at random, puts the marble back in the bag, and then selects another marble at random. How much greater is the probability of choosing a red marble and a green marble than the probability of choosing a red marble and a blue marble?

The probability of choosing each color marble is the ratio of the number of that color marble to the total number of marbles in the bag. There are 20 marbles in the bag. So, P(red)=6/20, p(blue) 5/20, p(green)=7/20, and p(yellow) = 2/20. The probability of choosing a red marble and a green marble is the product of the individual probabilities: P(red,green)=P(red)xp(green)=6/20x7/20=42/400. Similarly, the probability of choosing a red marble and a blue marble is P(red,blue)=P(red)xP(blue) = 6/20x5/20=30/400. The difference is 42/400-30/400=12/400=3/100. Answer: 3/100

Which of the following statements best describes the relationship between photosynthesis and respiration?

The products of photosynthesis are the reactants of respiration, and the products of respiration are the reactants of photosynthesis. Organisms that perform photosynthesis use the energy from sunlight to convert carbon dioxide and water into sugar and oxygen. During respiration, the opposite happens; organisms convert sugars and oxygen into carbon dioxide and water, in the process releasing energy.

The graphs of two linear equations intersect at a point in the first quadrant of the coordinate plane. One of the equations is 6x=8+2y. What equation could be another option?

The quickest solution is to determine the x- and y- intercepts for 6x=8+2y and for each of the four possible equations. Use the intercepts to sketch the graphs and answer the question. The intercepts of 6x=8+2y are )=(0, -4) and (4/3, 0), and those of y=2x+1 are (0,1) and (1/2, 0). It can be seen by drawing the lines that they must intersect in the first quadrant. Algebraically, the correct equation can be checked by finding the ordered pair of x and y values that satisfies the system of equations 6x= 8+2y and y=2x+1. Substitute 2x +1 for y in 6x=8+2y, so 6x=8+2(2x+1). Solving this leads to x=5 and y=11, a point in the first quadrant of the coordinate plane.

These dot plots show the heights, in inches, of boys and girls in the fourth grade at Lincoln Elementary School . Which of the following statements about the data sets is correct?

There are 16n data values for the girls heights. Because there is an even number of data values, the median value is the mean of the two middle values, which are the eighth and ninth values. Counting from the left side of the dot plot, the eighth and ninth values are 53 and 54. So, the median is 53.5 inches. Answer: The median of the girls heights is 53.5 inches.

A student builds a rubber-band guitar. Each rubber band produces a note at a different pitch. Which of the following actions should the student take to increase the pitch produced by a rubber band?

Tightening the rubber band. Rubber bands that vibrate more quickly produce sounds with higher pitches. Tightening a rubber band causes it to vibrate more quickly and therefore produces sounds with higher pitches. In contrast, rubber bands that are longer, thicker or weighted down by paper clips will vibrate more slowly.

A student bikes 3 miles to school in 20minutes. If there are approximately 1609 meters in a mile, which of the following expressions can the student use to calculate this speed in meters per second?

To convert from 3miles in 20minutes to meters per second, first divide by 60, the number of seconds in one minute. Based on this calculations, the student biked 3 miles in 1200 seconds. Then, multiply by the number of meters in one mile. 1609 Based on this calculation, the student biked 4827 meters in 1200 seconds. This will simplify to the rate in meters per second. Check that the units in minutes and miles cancel out the expressions, leaving meters and seconds.

Consider two angles. The measure of one angle is twice the measure of the other angle. Which of the following is correct?

Two angles with measures that add up to 180 deg are supplementary. If the measure of one angle is twice the measure of the other angle, then the smaller angle measures 60 deg and the larger angle measures 120 deg. Two angles with measures that add up to 90deg are complementary. If the measure of one angle is twice the measure of the other angle, then the smaller angle measures 30 deg and the larger angle measures 60 deg Answer is" If the angles are complementary, then the larger angle measures 60 deg

For healthy growth and development, varied and balanced diet for elementary students should contain more:

Unsaturated fats than saturated fats Some dietary fat is essential for children's growth and development. For children aged four and older, fat calories should make up about 25%-30% of total daily calories. Most fat in chidren's diet should come from polyunsaturated and monounsaturated fats such as those found in fish, nuts and vegetable oils. Excess levels of saturated and trans fat such as those found in meats; full-dairy products and processed foods, raises "bad" cholesterol and contributes to obesity, diabetes and heart disease. In contrast, oils derived form plants are high in unsaturated fats, which can raise "good' cholesterol levels and contribute to heart health.

Which of the following statements accurately describes a stage of the water cycle

Water vapor in the atmosphere condenses on dust particles to form clouds. The water cycle describes how water in all three states flows above, along, beneath Earth's surface. Water in gas form is called water vapor. As water vapor moves through the atmosphere, it sometimes collides with dust particles, loses energy, and condenses, or becomes liquid water. When this happens many times in the same part of the atmosphere, clouds form.

The best time to introduce a student to subtraction with two-digit numerals is:

When the student has achieved automatic response to subtraction facts. When the student has achieved automatic response to subtraction facts A student is not ready to solve more complex subtraction problems until he or she has mastered all the single-digit subtraction facts. Grade level, proficiency in addition, and the desire to move ahead are not sufficient indications of the student's readiness.

Cystic fibrosis is caused by a mutation to a certain gene. The allele with the mutation (c) is recessive, and the allele without the mutation (c) dominant. Which of the following genotypes represents a person who will likely develop cystic fibrosis?

cc only. The allele with the mutation for cystic fibrosis is recessive, so people with one or two normal alleles do not develop the disease. Only people who inherit the mutation from both parents (genotype cc) are at risk of developing cystic fibrosis.

Which of the following equations is an example of commutative property of multiplication *29x13=377 13x29=377

the commutative property of multiplication states that factors can be multiplied in any order and the product will be the same.

The factors (x-3), (x-4) and (x + 7) expand to give the equation:

x³ - 37x + 84 Multiplication of (x-3) by (x-4) yields the quadratic formula (x² - 7x + 12). When multiplied by the third factor (x + 7), this produces the formula: x3 - 37x + 84