Chapters 1-2
A bar code is what type of variable?
categorical variable
What are the four requirements for describing a scatterplot?
direction, form, strength, and unusual features (outliers)
When can we make inferences about a population?
When the sample is random or when it is an experiment.
How many outcomes would there be if you rolled two dice and flipped a coin?
72 outcomes
If you multiply your data by 4 and then add 2.35, what happens to the shape of the distribution?
shape stays the same
In an skewed left density curve, where is the mean in relation to the median.
mean < median
The weight gain of corals in aquariums where the water temperature is controlled at different levels. Identify the explanatory and response variables.
Explanatory Variable- water temperature
Response Variable- weight gain of corals
What are the 7 pitfalls of surveys?
nonresponse, truthfulness of response, faulty recall, hidden bias, vague wording, interviewer influence, and voluntary response
Interpret the probability that a randomly selected U.S. adult spends 2 minutes at a traffic light is 0.36.
Over many many trials, a U.S. adult will spend approximately 2 minutes at a traffic light 36% of the time.
When given a geometric distribution with p = 0.70 and when you look for the probability that Y = 9, what do you plug into the calculator?
geometpdf(0.7,9)
How do you find outliers?
Q1 - 1.5IQR and Q3 + 1.5IQR
Given x bar = 50, y bar = 87, r = 0.55, s sub x = 12, and s sub y = 15, find the equation for the linear regression.
y hat = 52.63 + 0.69x
What are the three types of experimental designs?
Randomized block design, completely randomized design, and matched pairs design
If 38% of people like mint gum, 14% like bubblegum, and 20% like both, what is the probability that a person will like mint or bubblegum?
0.32
What is the mean of a geometric random variable y of p = 0.777?
1.29
What is the rule for finding 1-3 standard deviations away from the mean of a Normal Distribution Curve?
68-95-99.7 Rule
If the coefficient of determination is 0.60032, what is the correlation?
0.77480
cluster sampling
If you roll a fair 6 sided die 10 times, what is the probability that you get at least one 3?
0.8385
Find the expected value of x when
x: 0 1 2 3 4 5
p: .17 .30 .06 .10 .07 .30
2.5
What two rules must a density curve obey?
Must be on or above the horizontal axis.
The area must equal 1.
If a regression line is appropriate, what should the regression plot look like?
There should be very small residuals with no left over curved pattern.
What are the four principles of experimental design?
comparison, random assignment, control, and replication
If you flip a coin 5 times and get THHTH, what is the probability the next toss will be a heads?
0.5
You shuffle a deck of cards and pick a random card and then put it back. You count how many times it takes to get a king. What type of distribution is this?
geometric