General Science: Chapter 3
Do the dimensional analyses: 140 cm -> in -> feet 1 in= 2.54 cm 1 ft= 12 in
55.11 inches 4.59 ft
Calculate error: Measurements 34.5, 34.6, 34.4, 34.5 True value 37.2
7.26%
Probability formulas
# of favorable outcomes/ # of total outcomes
How to calculate error
% error= Avg -true value /true value * 100 (always positive)
What do bar charts usually compare or show
Usually comparing unrelated groups
You are measuring the length of a table using a meter stick. After measuring the table, you notice that the end of the meter stick is broken o just below the 3 cm mark. What kind of error is this likely to introduce in your measurement? a) parallax error b) precision error c) systemic error d) random error
c
You measure the mass of piece of gold to be 45.8 g, but the true value is 48.0 g. What is the percent error? a) 0.9542% b) 95.42% c) 4.58% d) 0.0458%c
c
Find the range for one standard deviation in the following data set: 16, 20, 14, 24, 16, 19, 30, and 8 a) 0 to 18.375 b) 12.175 to 19.35 c) 8 to 30 d) 12.175 to 24.575 e) 8 to 18.375
d
Find the standard deviation for the following data set: 16, 20, 14, 24, 16, 19, 30, and 8 a) 38.48 b) 307.87 c) 5.4 d) 18.375 e) 6.2
d
Find the variance for the following data set: 16, 20, 14, 24, 16, 19, 30, and 8 a) 1.625 b) 2.64 c) 39.2 d) 38.48 e) 18.375
d
If all other statistical procedures fail, the best predictor of a score will be the _____. a) sample size b) median c) mode d) mean
d
Using a standard deck of 52 cards, what is the probability of selecting a 4 and then after not replacing the card, selecting another 4? a) 1/169 b) 12/2652 c) 3/51 d) 1/221
d
Which of the following is NOT an example of a potential use of a computer model? a) Modeling fire for a Hollywood movie b) Predicting the course of climate change c) Simulating car crashes for safety tests d) Creating a flowchart of how an office works
d
Which of the following is least likely to be reported due to it being the one most likely to change by the introduction of additional scores? a) Median b) Mean c) Population size d) Mode
d
Which rule describes how you come to understand what a chart means and how to use it effectively? a) Ask a fellow student. b) Take five minutes to read through the questions. c) Answer the question on your own. d) Identify the trends of the chart.
d
Which rule describes the very first thing you should do when encountering a problem involving a graph or chart? a) Identify the trends of the chart. b) Skip the problem and move on. c) Take five minutes to read through the questions. d) Orient yourself to the x and y axes.
d
Why do scientists revise models? a) Because scientists often turn out to be wrong. b) To fit their personal ideologies. c) Because the way the natural world works changes over time. d) Because science is always open to new data, and sometimes our understanding is simplified or limited.
d
Independent or dependent events: Probability of pulling an ace twice w/o replacing
dependent
Find the standard deviation for the following data set: 101, 106, 125, 142, 78, and 109 a) 25.6 b) 21.2 c) 110 d) 395 e) 19.9
e
Dimensional analysis
method to convert one different type of unit to another
How is mean interpreted
most likely to happen
How should median be used
Good for lots of lows and high in data (outliers)
What do pie charts usually compare or show
How different groups make up percentages of something
What do flow charts usually compare or show
How steps are related
Measures of central tendency
Set of descriptive measures which indicate the typical score (high probability). Mean, median, mode
Variance
Average of each distance from the mean squared
How to find standard deviation
Calculate mean, subtract mean from each value, square differences Mean, square root of total
Line graph are usually used to show what or compare
Depicts direct relationship between the dependent and independent variables
Random error
Due to unpredictable & uncontrollable factors that can affect the experiment
Systematic error
Error caused by measure equipment
Parallax error
Error due to observing a measuring device at angle
Dependent events
Events in which the previous attempts affect the outcomes of subsequent events
Independent events
Events that do not affect the outcome of subsequent events (separate)
Independent or dependent events: Rolling dice & get 2, roll again & get 2
Independent
Median
Middle score after the scores have been arranged in numerical order
Mode
Most often occurring factor
Two categories for sources of error
Systematic & random error
Standard deviation
The measure of how closely all of the data in a data set surrounds the mean
Which rule describes what you should do when you're ready to read a multiple-choice question? a) Take five minutes to read all the questions. b) Take five minutes to understand the chart. c) Answer the question before looking at the answer choices. d) Identify the trends of the chart.
c
If there are two modes, you should _____. a) report both b) report the one closer to the mean c) report the higher of the two numbers d) find the average
a
If you roll a die three times, what is the probability of rolling only even numbers? a) 1/8 b) 1/4 c) 1/2 d) 1/6
a
What is a scientific model? a) A representation of a particular phenomena using something else to make it easier to understand b) Any physical form created by scientists to represent something c) A set of mathematics that describe a particular situation d) A person who is showing off the latest styles in lab coats
a
Which of the following is NOT a type of scientific model? a) Photograph model b) Computer model c) Mathematical model d) Visual model
a
_____ is how close a measurement is to the true or accepted value, while _____ measures how repeatable a measurement is. a) accuracy; precision b) systemic error; random error c) precision; accuracy d) parallax; percent error
a
Which type of chart compares data with relative percentages? a) Line Graph b) Bar Chart c) Pie Chart d) Flow Chart
c
Which type of chart illustrates relationships between concepts or steps in a process? a) Line Graph b) Pie Chart c) Flow Chart d) Bar Chart e) Table
c
Which type of chart plots the relationship between dependent and independent variables? a) Pie Chart b) Flow Chart c) Line Graph d) Bar Chart
c
Outlier
a point of data that is distant from others
Probability
a ratio that states the likelihood of the events happening
Mean
average score of the sample
All of the letters that spell MISSISSIPPI are put into a bag. What is the probability of selecting a vowel, and then after replacing the letter, also drawing an S? a) 8/55 b) 16/121 c) 4/11 d) 16/110
b
Find the variance for the following data set: 101, 106, 125, 142, 78, and 109 a) 2370 b) 395 c) 1988 d) 110 e) 31
b
How many quarts are there in 5.0 liters? Conversion factor: 1 L = 1.0567 quarts a) 55 quarts b) 5.3 quarts c) 0.95 quarts d) 5 quarts
b
What should you do to mitigate the effects of random error? a) Perform a measurement only one time so that there won't be a chance to introduce more errors b) Repeat a measurement several times and find an average c) Make sure your measuring instrument is working correctly and is properly calibrated d) Make sure you are not looking at the measuring instrument at an angle
b
Which variable remains unaffected by the other variables of an experiment? a) None of these answers are correct. b) Independent variable c) Dependent variable d) Y variable
b
All of the following statements are correct, EXCEPT: a) The mean is also known as the average. b) An outlier is likely to skew the mean of a sample. c) An outlier is likely to skew the median more than the mean of a sample. d) A good sample should be representative of the population.
c
All of the letters of MISSISSIPPI are put in a bag. What is the probability of selecting an M and then after not replacing the letter, selecting a P? a) 1/110 b) 2/121 c) 1/55 d) 1/121
c
An object has a velocity of 72 km/hr. Find its value in m/s. Conversion factors: 1 hr = 3600 s 1000 m = 1 km a) 0.00002 m/s b) 259.2 m/s c) 20 m/s d) 25920 m/s
c
Convert 1.5 square miles (miles^2) to square meters (m^2). Conversion factor: 1609.34 meter = 1 mile a) 0.00093 square meters b) 2414 square meters c) 3,884,963 square meters d) 0.00000058 square meters
c
The following data represents the test scores of eight students in Mr. Miller's science class. 92%, 91%, 89%, 95%, 45%, 88%, 90%, 91% The student who got a 45% is _____. a) the median b) the mode c) an outlier d) a representative sample
c
Two students perform the same experiment and calculate the percent error of their measurement. Student #1 has a percent error of 14.2%, while student #2 has a percent error of 9.4%. Which student has the most accurate measurements? a) You can't tell because % error measures precision and not accuracy. b) Student #1 c) Student #2 d) You can't tell because you need to know the true value before you can know which is most accurate
c
Using a standard deck of cards (which has 26 red cards and 26 black cards, with 13 cards of every suit), what is the probability of selecting a red card, and then after replacing the card, selecting a heart card? a) 338/2652 b) 312/2652 c) 1/8 d) 26/221
c
What conversion factor do we multiply to 120 minutes if we want to convert it to hours? a) 2 hr/60 minutes b) 60 minutes/1 hr c) 1 hr/60 minutes d) 1 hr/60 seconds
c
Which axis is the horizontal axis? a) None of these answers are correct b) Y axis c) X axis d) Z axis
c
Which of the following is the main benefit of a visual model? a) It's a perfectly accurate depiction of the real world. b) It allows you to make predictions more quickly then the human brain is able to. c) It makes things easier to understand, and so can be used for communication and education. d) None of the other answers are correct.
c
Normal distribution
represented when the majority of the data is found close to the average of the set
What is normal deviation
within one deviation mean
y-axis & x-axis = which variables/ horizontal or vertical
y= dependent, vertical x= independent, horizontal
