stats
.939
Enter the numerical value of the correlation coefficient. Round to three decimal places.
Because colas tend to replace healthier beverages and colas contain caffeine and phosphoric acid, researchers wanted to know whether cola consumption is associated with lower bone mineral density in women. The accompanying data lists the typical number of cans of cola consumed in a week and the femoral neck bone mineral density for a sample of 15 women. Interpret the slope. Select the correct choice below and, if necessary, fill in the answer box to complete your choice. Interpret the y-intercept. Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
For every cola consumed per week, the bone density decreases by .026 g/cm^3, on average. For 0 colas consumed in a week, the bone density is predicted to be . 900 g/cm^3.
Interpret the slope and y-intercept, if appropriate. Choose the correct answer below and fill in any answer boxes in your choice.
For every pound added to the weight of the car, gas mileage in the city will decrease by 0.00634 mile(s) per gallon, on average. It is not appropriate to interpret the y-intercept.
Which histogram depicts a higher standard deviation?
Histogram (b) depicts the higher standard deviation, because the distribution has more dispersion. 0-10 vs 0-60 on a graph
Which measure of central tendency best describes?
Mean is the most frequently used measure of central tendency and generally considered the best measure of it. However, there are some situations where either median or mode are preferred. Median is the preferred measure of central tendency when: There are a few extreme scores in the distribution of the data.
Determine if the following probability experiment represents a binomial experiment. A random sample of 30 high school seniors is obtained, and the individuals selected are asked to state their heights.
No, this probability experiment does not represent a binomial experiment because the variable is continuous, and there are not two mutually exclusive outcomes.
is the table above an example of a probability model?
No, because the probabilities do not sum to 1.
Is it reasonable to interpret the y-intercept? Why? Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
No—a house of 0 square feet is not possible and outside the scope of the model.
A frequency distribution lists the _________ of occurrences of each category of data, while a relative frequency distribution lists the _________ of occurrences of each category of data.
Number proportion
If P(E)=0.50,P(E or F)=0.60,and P(E and F)=0.05,find P(F).
P(F)=. 15.15
a b c
P(club or spade)=. 5 P(club or spade or diamond)=. 75 P(four or diamond)=. 308
The standard deviation increases and the interquartile range is not affected. What property does this illustrate? Choose the correct answer below.
Resistance
false
Standard deviation is a measure that is resistant.
The proportion of San Marcos residents in the health official's sample who were diagnosed with influenza
Suppose a public health official wants to estimate the true proportion of San Marcos residents who were diagnosed with influenza last year. The public health official randomly selects 2000 medical records of the people who visited their doctor in the last year. She records whether a diagnosis of influenza appears in the medical record and then computes the proportion of people diagnosed with influenza among the 2000 individuals. Select the statement that correctly identifies the statistic in this example.
Which sampling method does not require a frame?
Systematic
16%
The distribution of exam scores for a biology class was approximately symmetric with a mean of 65 and standard deviation of 9 points. Use the Empirical rule to determine approximately what percentage of students scored an 74 or higher?
If the pediatrician wants to use height to predict head circumference, determine which variable is the explanatory variable and which is the response variable.
The explanatory variable is height and the response variable is head circumference.
Determine which variable is the explanatory variable and which is the response variable.
The explanatory variable is the weight and the response variable is the miles per gallon
skewed left
The following values shows the monthly demand of air filters for a company in the last year and January of this year. Use this data for the next four questions. 16, 26, 48, 50, 73, 77, 71, 68, 70, 90, 81, 67, 86 Describe the shape of the distribution.
Suppose a life insurance company sells a $150,000 one-year term life insurance policy to a 22-year-old female for $240. The probability that the female survives the year is 0.999584. Compute and interpret the expected value of this policy to the insurance company.
The insurance company expects to make an average profit of $177.60 on every 22-year-old female it insures for 1 year. The expected value is $177.60
A man has four shirts and three ties. Assuming that they all match, how many different shirt-and-tie combinations can he wear?
The man can wear 12 different shirt-and-tie combinations.
A lottery exists where balls numbered 1 to 22 are placed in an urn. To win, you must match the four balls chosen in the correct order. How many possible outcomes are there for this game?
The number of possible outcomes is 175560
Find the probability P(Ec)if P(E)=0.36.
The probability P(Ec) is .64
In a certain lottery, an urn contains balls numbered 1 to 25. From this urn, 6 balls are chosen randomly, without replacement. For a $1 bet, a player chooses one set of six numbers. To win, all six numbers must match those chosen from the urn. The order in which the balls are selected does not matter. What is the probability of winning this lottery with one ticket?
The probability of winning is 5.65 times 10 Superscript negative 65.65×10^−6.
A survey of 600 randomly selected high school students determined that 538 play organized sports.
The probability that a randomly selected high school student plays organized sports is . 897
A golf ball is selected at random from a golf bag. If the golf bag contains 3 black balls, 6 green balls, and 11 red balls, find the probability of the following event. The golf ball is black or green.
The probability that the golf ball is black or green is . 45
Suppose you toss a coin 100 times and get 58 heads and 42 tails. Based on these results, what is the probability that the next flip results in a head?
The probability that the next flip results in a head is approximately . 58
Suppose a shipment of 140 electronic components contain 3 defective components. To determine whether the shipment should be accepted, a quality-control engineer randomly selects 3 of the components and tests them. If 1 or more of the components is defective, the shipment is rejected. What is the probability that the shipment is rejected?
The probability that the shipment is rejected is . 0634
Find the probability P(E or F) if E and F are mutually exclusive, P(E)=0.41,and P(F)=0.47.
The probability P(E or F) is . 88
In a statistics class, the standard deviation of the heights of all students was 4.1 inches. The standard deviation of the heights of males was 3.5 inches and the standard deviation of females was 3.4 inches. Why is the standard deviation of the entire class more than the standard deviation of the males and females considered separately?
The standard deviation of the entire class is more than the standard deviation of the males and females considered separately because the distribution of the entire class has more dispersion.
Four members from a 40-person committee are to be selected randomly to serve as chairperson, vice-chairperson, secretary, and treasurer. The first person selected is the chairperson; the second, the vice-chairperson; the third, the secretary; and the fourth, the treasurer. How many different leadership structures are possible?
There are 2193360 possible different leadership structures.
Determine why it is not a probability model. Choose the correct answer below.
This is not a probability model because at least one probability is less than 0.
quadratic model
Use the jmp output below. Which model would provide the stronger prediction for death rate given birth rate?
mean
Which statistical measure is known as the "weighted center"? Type your response as a single word only using all lowercase letters.
Are E and G mutually exclusive?
Yes, because the events E and G have no outcomes in common. E and G={}
Does a linear relation exist between height and head circumference?
Yes, the variables height and head circumference are positively associated because r is positive and the absolute value of the correlation coefficient is greater than the critical value
Does a linear relation exist between the commute time and well-being index score?
Yes, there appears to be a negative linear association because r is negative and is less than the negative of the critical value.
what is relative frequency?
(decimal or percent) the average number of occurrences of a particular event in a large number of repeated trials
The sum of the deviations about the mean always equals
00
What is the probability of an event that is impossible?
00
14|1 is
14.1
Find the value of the combination. 6C2
15
no outliers
16, 26, 48, 50, 73, 77, 71, 68, 70, 90, 81, 67, 86 Are there any outliers for this data set, if so what numbers are outliers?
30
16, 26, 48, 50, 73, 77, 71, 68, 70, 90, 81, 67, 86 Calculate the innerquartile range for the data set
lower outlier boundary = 4, upper outlier boundary = 124
16, 26, 48, 50, 73, 77, 71, 68, 70, 90, 81, 67, 86 Calculate the lower and upper outlier boundaries
A salesperson must travel to four cities to promote a new marketing campaign. How many different trips are possible if any route between cities is possible?
4!
Find the value of the factorial. 8!
40320
5.5
5.5
6.1/6.2
6.1/6.2
Explain the meaning of "The 90th percentile of the waist circumference of females 2 years of age in a certain city is 49.8 cm."
90% of 2-year-old females have a waist circumference that is 49.8 cm or less.
A sample of convenience most likely to contain bias and under-representation
A dietitian wants to start a new program at her university to assist students in the healthy eating. She sets up a table at one of the on-campus dining halls and gives a survey to collect information about students' overall eating habits.
Compute the residual.
A residual is the difference between the observed and predicted values of y.
The residual plot shows curvature, this means a quadratic model should be explored
A residual plot was constructed using the same data in the previous question. Select the correct interpretation of the residual plot.
what does confounding even mean?
Confounding in a study occurs when the effects of two or more explanatory variables are not separated. Therefore, any relation that may exist between an explanatory variable and the response variable may be due to some other variable or variables not accounted for in the study.`
A magazine asks its readers to call in their opinion regarding the amount of advertising in the present issue. What type of sampling is used?
Convenience
what does it mean to be strong positive or strong negative
Describe the strength of the linear association between the two variables.
quantitive continuous
Distance from your home to Texas State University is what type of variable?
For proportions: What percentage of households has one or two children under the age of 5?
add two numbers together then divide
What is a confounding variable?
an explanatory variable that was considered in a study whose effect cannot be distinguished from a second explanatory variable in the study.
What is a lurking variable?
an explanatory variable that was not considered in a study, but that affects the value of the response variable in the study. In addition, lurking variables are typically related to explanatory variables in the study.
chapter 2
chapter 2
chapter 3.1/2
chapter 3.1/2
chapter 4.1
chapter 4.1
chapter 5.1/ 5.2
chapter 5.1/ 5.2
negative r value
graph starts at top left
z score calculator (not raw data)
https://www.socscistatistics.com/tests/ztest/zscorecalculator.aspx
What do we call the outcome "yellow"?
impossible event
What measure of central tendency best describes the "center" of the distribution?
median
Suppose that a probability is approximated to be zero based on empirical results. Does this mean that the event is impossible?
no
red 0.1 green 0.1 blue 0.35 brown 0.25 yellow 0 orange 0.15
probability model
Toshiba wants to administer a satisfaction survey to its current customers. Using their customer database, the company randomly selects 80 customers and asks them about their level of satisfaction with the company. What type of sampling is used?
simple random
To determine her blood sugar level, Samantha divides up her day into three parts: morning, afternoon, and evening. She then measures her blood sugar level at 2 randomly selected times during each part of the day. What type of sampling is used?
stratified
A ______ is obtained by dividing the population into homogeneous groups and randomly selecting individuals from each group.
stratified sample
symmetric not uniform
symmetric not uniform when describing histogram
o estimate the percentage of defects in a recent manufacturing batch, a quality control manager at Toshiba selects every 12th laptop that comes off the assembly line starting with the seventh until she obtains a sample of 110 laptops. What type of sampling is used?
systematic
What is frequency?
the amount (not a percent or decimal)
Verify that this is a discrete probability distribution.
this is a discrete probability distribution because all of the probabilities are between 0 and 11, inclusive, and the sum of the probabilities is 11.
For the histogram on the right determine whether the mean is greater than, less than, or approximately equal to the median. Justify your answer.
x>M because the histogram is skewed right.
A standard deck of cards contains 52 cards. One card is selected from the deck.
(a) Compute the probability of randomly selecting a club or spade. (b) Compute the probability of randomly selecting a club or spade or diamond. (c) Compute the probability of randomly selecting a four or diamond.
Scores of an IQ test have a bell-shaped distribution with a mean of 100 and a standard deviation of 12. Use the empirical rule to determine the following. (a) What percentage of people has an IQ score between 64 and 136? (b) What percentage of people has an IQ score less than 88 or greater than 112? (c) What percentage of people has an IQ score greater than 136?
(a) 99.7% (Type an integer or a decimal.) (b) 32% (Type an integer or a decimal.) (c) .15% (Type an integer or a decimal.)
Is a multiple birth involving a mother who was at least 40 years old unusual?
No, because the probability of a multiple birth involving a mother who was at least 40 years old is greater than 0.05.
Find the probability of the indicated event if P(E)=0.30 and P(F)=0.45. Find P(E and F) if P(E or F)=
P(E and F)=. 25.25
Find the probability of the indicated event if P(E)=0.40 and P(F)=0.50. Find P(E or F) if P(E and F)=0.15.
P(E or F)=. 75
Would you consider it unusual to find a college student who never wears a seat belt when riding in a car driven by someone else?
Yes, because P(never)<0.05.
Explain the meaning of "The 10th percentile of the head circumference of males 3 to 5 months of age in a certain city is 41.5cm."
10% of 3- to 5-month-old males have a head circumference that is 41.5 cm or less
3.4.5
3.4.5
For each 1 cm increase in hip circumference the percent of body fat increases by 0.677%, on average
A linear model was calculated using hip circumference (in cm) as an explanatory variable to estimate the amount of body fat (as a percent). View scatterplot here if image is small and you need to enlarge. Select the correct interpretation of the slope of the line.
systematic
A study was done to determine the age, number of times per week, and duration (amount of time) of residents using a local park in San Antonio, Texas. The first house in the neighborhood around the park was selected randomly, and then the resident of every eighth house in the neighborhood around the park was interviewed. Identify the correct sampling method.
Anthropometry involves the measurement of the human body. One goal of these measurements is to assess how body measurements may be changing over time. The included table represents the standing height of males aged 20 years or older for various age groups in a certain city in 2015. Based on the percentile measurements of the different age groups, what might you conclude?
At each percentile, the heights generally decrease as the age increases. Assuming that an adult male does not grow after age 20, the percentiles imply that adults born in 1990 are generally taller than adults who were born in 1950.
confounding variable
Because colas tend to replace healthier beverages and colas contain caffeine and phosphoric acid, researchers and associates wanted to know whether cola consumption is associated with lower bone mineral density ( in women. In a sample of 15 women, the average number of colas consumed per week and the femoral neck bone mineral density was measure. Recent pregnancy and lactation would be considered as what type of variable if researchers did not consider this variable in the study, yet previous studies indicate this variable is associated with bone mineral density loss.
false
Because colas tend to replace healthier beverages and colas contain caffeine and phosphoric acid, researchers and associates wanted to know whether cola consumption is associated with lower bone mineral density in women. In a sample of 15 women, the average number of colas consumed per week and the femoral neck bone mineral density was measured. True or False: Based on this study, researchers can conclude that increased cola consumption causes a decline in bone mineral density in women?
number of colas consumed per week
Because colas tend to replace healthier beverages and colas contain caffeine and phosphoric acid, researchers and associates wanted to know whether cola consumption is associated with lower bone mineral density in women. In a sample of 15 women, the average number of colas consumed per week and the femoral neck bone mineral density was measured. What is the explanatory variable?
observational study
Because colas tend to replace healthier beverages and colas contain caffeine and phosphoric acid, researchers want to know whether cola consumption is associated with lower bone mineral density in women. In a sample of 15 women, the average number of colas consumed per week, and the femoral neck bone mineral density were measured. Use this information and the scatterplot to answer this question and the next three questions.
What does it mean if a statistic is resistant?
Extreme values (very large or small) relative to the data do not affect its value substantially.
.583
The average for Professor Kyle's statistics exam was an 80 with a standard deviation of 5 points. The average for Professor Gia's statistics exam was a 70 with a standard deviation of 12 points. Eric scored 82 in Professor Kyle's class, while Zandra scored a 77 in Professor Gia's class. Calculate the z-score for Zandra.
zandra
The average for Professor Kyle's statistics exam was an 80 with a standard deviation of 5 points. The average for Professor Gia's statistics exam was a 70 with a standard deviation of 12 points. Eric scored 82 in Professor Kyle's class, while Zandra scored a 77 in Professor Gia's class. Calculate the z-scores for each student. Which student scored higher relative to their population?
Approximately 23.6% of the variation in death rate is explained by birth rate in the linear model.
The birth rate and death rate per 1,000 individuals was recorded for each country by the World Bank. A linear regression model was created to predict the death rate using birth rate as the explanatory variable. Select the correct interpretation for the coefficient of determination. value. Use this link if you need to enlarge the image.
15.4
The capacities of several metal containers are: 38, 18, 37, 64, and 27 liters. What is the population standard deviation in liters?
46
The capacities of several metal containers are: 38, 18, 37, 64, and 27 liters. What is the range in liters?
median
The following graph presents data gathered while observing a waiting line in a bank. The data was gathered during the weekdays. Periods of the time were selected at random, between 9:30 am and 10:30 am. Each time, the number of people waiting in line was recorded. One hundred observations were collected. Which measure would be most appropriate as a measure of center for this data?
A researcher wanted to determine the number of televisions in households. He conducts a survey of 40 randomly selected households and obtains the data in the accompanying table.
The given data are discrete because they can only have whole number values.
According to a certain country's department of education, 40.9% of 3-year-olds are enrolled in day care. What is the probability that a randomly selected 3-year-old is enrolled in day care?
The probability that a randomly selected 3-year-old is enrolled in day care is . 409
In a certain game of chance, a wheel consists of 60 slots numbered 00, 0, 1, 2,..., 58.
The sample space is {00, 0, 1, 2,..., 58}.
Predict the final exam score for a student who misses five class periods.
To determine if there is a linear relation between the number of days absent and the student's final exam score, compare the correlation coefficient to a critical value. Use technology to find the correlation coefficient, rounding to three decimal places. r=−0.954 Find the critical value for n=10. The critical value is 0.632. There is a linear relation because the absolute value of the correlation coefficient (0.954) is greater than the critical value (0.632). Since there is a linear relation, substitute x=5 into the regression line equation and solve for y to predict the final exam score for a student who misses five class periods, rounding to two decimal places as needed. y=−2.795(5)+89.905=75.93
To determine customer opinion of their food quality, General Foods randomly selects 90 city blocks during a certain week and surveys all homes within the city blocks. What type of sampling is used?
cluster
A ________ is obtained by dividing the population into groups and selecting all individuals from within a random sample of the groups.
cluster sample
the conversion to centimeters
had no effect on r
0, −0.45, 0.34, 1, 0.04,
he numbers that could be a probability of an event are 0 comma . 34 comma 1 comma . 040,.34,1,.04.
standard deviation calculator for raw data
https://www.calculator.net/standard-deviation-calculator.html?numberinputs=20%0D%0A12%0D%0A3%0D%0A6%0D%0A9&ctype=s&x=95&y=20
sample variance calculator (s^2)
https://www.calculatorsoup.com/calculators/statistics/variance-calculator.php
critical value calculator
https://www.socscistatistics.com/tests/criticalvalues/default.aspx
Determine the linear correlation coefficient between two things
https://www.socscistatistics.com/tests/pearson/default2.aspx
Which variable is likely the explanatory variable and which is the response variable?
the explanatory variable is commute time and the response variable is the well-being score because commute time affects the well-being score.
the more r is closer to one
then the more linear it will be
this exam 1
this is exam 1
In a probability model, the sum of the probabilities of all outcomes must equal 1.
true
The phone company decides to use the upper fence as the cutoff point for the number of minutes at which the customer should be contacted. What is the cutoff point?
use a box plot
A certain standardized test's math scores have a bell-shaped distribution with a mean of 530 and a standard deviation of 110. Complete parts (a) through (c).
(a) What percentage of standardized test scores is between 200 and 860? 99.7% (b) What percentage of standardized test scores is less than 200 or greater than 860? .3.3% (c) What percentage of standardized test scores is greater than 750? 2.5%
