Question 1

Data Set "Marriage vs The Economy"

Solution: There is a negative correlation between "Median Hourly Wages" and "# of marriages"

Question 2

 Match the following scatter plots A, B and C to  linear correlation coefficient values, r = – 0.97, 0.41 or 0.83 .

Scatter Plot A

Scatter Plot B

Scatter Plot C

Question 3

1. If we had data that displayed very strong negative correlation, we would expect to get a linear correlation coefficient "close" to what integer? 

2. If we saw a scatterplot that had very strong positive correlation, with all of the data values very very close to the regression line, we would expect to have residuals that are "close" to what integer? 

Question 4

In StatCrunch, open the shared data set Absences vs Grade (Marks), owned by mortensenn. Perform a linear regression analysis using using Absences as the explanatory variable and Grade (Marks) as the response variable.

a) Give the correlation coefficient. Round your answer to two decimal places. 

b) Give the amount of variation in Grade that is explained by Absences.  %.    Give your answer as a percent rounded to two decimal places. (Be sure you do your rounding only after you convert to a percent).   

c) By what amount do we expect the Grade to vary from what is predicted by the regression equation?  Give your answer rounded to two decimal places. 

d) Predict the Grade for someone with 3 absences using this model.  Round your answer to two decimal places.

f) Give a number of absences that shouldn't be used for a predictor with this model. 

Question 5

In StatCrunch, open the data set titled Galton Data owned by msullivan13803. Perform a linear regression analysis using the column Father as the explanatory variable and Son as the response variable. This will use the Father's height as a predictor for the sons height.

a) Give a statement to interpret the slope of the regression equation.

b) Should this linear regression regression model be used to predict the height of a Son using that of the Father? Why or why not?

Give your answer here in Canvas if you will keyboard, or on a document to submit if you will write by hand. 

Question 6

What is the probability that someone who Has NOT Received at least one dose of a Covid-19 Vaccine identified as White? Give the numerator and denominator of the fraction that will identify this probability.

Numerator (top) = 

Denominator (bot) = 

Question 7

Consider the following partially completed Two-Way Table.

   

Identify with the Democratic Party

Do Not   Identify with the Democratic Party

 

Age: Millennial (Ages 24 – 39)

A

B

C.    220,000

 

Age: Not a Millennial

D

E

F.    780,000

  

G.    330,000

H.    670,000

I.    1,000,000

Use the following information to find the value of box B.

A recent Pew Research Poll, June 2, 2020, Reveals the 46% of Millennials DO NOT Identify with the Democratic Party.

Question 8

Suppose the random variable X = The number of times I have gone out to get afternoon coffee in a week.

Is X a discrete or continuous random variable? 

Group of answer choices

Continuous

Discrete

Question 9

Suppose the random variable X = weight of a students backpack.

Is X a discrete or continuous random variable? 

Group of answer choices

Discrete

Continuous

Question 10

A. As an event gets more and more likely, the probability of that event gets closer and closer to  . (Enter an integer.)

B. As an event gets less and less likely, the probability of that event gets closer and closer to  . (Enter an integer).

C. Suppose the probability of an event is .014, we expect that event to happen about what percent of the time?  %  (Enter a number to one decimal place.)

D. Suppose the probability of an event is .2413. If we conducted 100 trials of the corresponding probability experiment, we would expect this even to happen about how many times out of the 100 trials.  (Enter an integer)

Question 11

The following table shows the probability distribution for X = Number of coffee drinks bought per week per student during one semester at a community college. Find the missing value to complete the table.

 

P(X = 3) = 

Question 12 

In StatCrunch, load the shared data set Sweet Treats owned by slohse. The data table gives a Discrete Probability Distribution for the number of Sweet Treats purchased per week, along with their corresponding probabilities.

A. It would be unusual that I would buy how many sweet treats? 

B. What is the probability of buying 2 or fewer sweet treats? 

C. What is the probability of buying 3 or more sweet treats? 

D. Which is more likely? B = buying 2 or fewer sweet treats or C = buying 3 or more sweet treats? (Answer either B or C) 

Question 13

Rabbit weights have a mean of 12 lbs and a standard deviation of 2 lbs.

Answer the following questions regarding z-scores. (Note – you shouldn't need a formula to get any of these answers, just an understanding of what a z-score represents.)

A. What would be the z-score for a rabbit weight of 12 lbs? z =  (Enter an integer)

B. What would be the weight for a rabbit with a z-score of -1? Weight=  (Enter an integer)

C. What would be the z-score for a rabbit weight of 8 lbs? z =  (Enter an integer)

Question 14

Consider the following normal distribution and answer the question below. Assume horizontal axis is standard, with numbered values corresponding to z-scores of -3, -2, -1, 0, 1, 2, 3.

  

 What is the mean of the data set represented in this distribution?   .

 What is the standard deviation of the data set represented in this distribution? 

 According to this distribution, is an outcome near 6 or 1 more likely? 

Question 15

Data analysis of the StatCrunch shared data set containing characteristics of cereal shows that the variable Calories per Serving follows a roughly bell-shaped curve, with a mean of 106.9 calories and a standard deviation of 19.5 calories.

a) Find the probability that a randomly selected cereal has less than 100 calories per serving.  Give your answer to four decimal places.

b) Find the probability that a randomly selected cereal has between 100 and 130 calories.  Give your answer to four decimal places. 

c) Which is more likely, to select a cereal that has A = less than 100 calories, or B= between 100 and 130 calories?  Answer A or B