Many drivers of cars that can run on regular gas instead buy premium gas in the belief that they will get better gas mileage (miles per gallon). To test that belief, a sample of 10 cars was obtained from a company fleet where all the cars can run on regular gas. Each car is filled first with either regular or premium gasoline, as decided by a coin toss, and the mileage for that full tank of gas is recorded. The mileage is again recorded for the same cars with full tank of gas of the other kind of gasoline. The car drivers were unaware that they were participating in an experiment. Research Question: Does the data suggest, on the average, that cars had a higher gas mileage (in miles per gallon) with premium gas  when compared to regular gas? This is an example of paired data because there are two recorded measurements for each .  On the average, 2.0 miles per gallon was achieved with premium gas.  When using the paired t procedure, we successful in reducing variation between the types of gasoline, because the standard deviation for the differences: sd = miles per gallon is the standard deviations found with the original two samples for Premium and Regular gas.

Consider each scenario and decide which statistical procedure should be used to answer the question. Scenario A: On average, do people who regularly exercise have a lower resting pulse rate (beats/minute)  when considering Stat 200 students. A random sample 40 Stat 200 students who regularly exercise and a random sample of 40 Stat 200 students who don’t regularly exercise were obtained.  The resting pulse rate was determined for each Stat 200 student. Scenario B: On average, do most people desire to be taller?  A random sample of adults were asked:  what is your actual height (inches) and what is your ideal height (inches).  A difference was computed for adult person when considering the two samples.  With Scenario A, we should use the procedure.   With Scenario B, we should use the procedure.

Using a random sample of 1,017 adults living in all 50 states and the District of Columbia, Gallup calculated that 33% of Americans are confident they will have enough money in retirement. The margin of error is ±4 percentage points at the 95% confidence level. Classify the statements below as true or false:

Consider the StatKey output below that provides a bootstrap distribution for the difference in proportions: Use all provided information.  The normal approximation of this bootstrap distribution is: N(

Researchers from Gallup used a random sample of n = 1503 adults in the US who were asked whether they drove a car every day of the week.  The proportion who said “yes” was 0.62 with a margin of error of 0.04. What is the correct calculation for the interval estimate for the population proportion who drove a care every day of the week?

Researchers test the provided hypotheses about two variables: ‘Favorite type of Apple’ (Red Delicious, Granny Smith, Honeycrisp, Empire, Gala) and ‘Time Zone where you Live: ‘(Pacific, Mountain, Central, Eastern) when based on a sample of n = 200 U.S. adults. H0: There is no association between favorite type of apple and time zone where you live. Ha: There is an association between favorite type of apple and time zone where you live Assume the researchers calculated a p-value of 0.246.  What is the correct conclusion for this hypothesis test using a significance level of 0.05?

Researchers surveyed n = 25 stat 200 male students to determine if they consume 3 or more alcoholic beverages per week. Their goal was to see if more than 50% of male students consume 3 or more alcoholic beverages per week. The relevant sample statistic is 0.60 (60%) with a standard error of 0.10.  The p-value is 0.159. Correctly complete the p-value interpretation below: The chance of seeing a test statistic of = or any value is , if in fact the hypothesis is true.

Research Question:  What percent of Stat 200 students regularly complete the lab worksheet prior to their scheduled lab class?    The parameter of interest is a . To answer this question, we should .  

Consider the StatKey output below that provides a bootstrap distribution for the mean     Use all provided information. The normal approximation of this bootstrap distribution is: N(μ=, σ=) .

Research Question: Are dog owners more likely to be extroverted when compared to cat owners? The parameter of interest is a . To answer this question, we should .