Blog

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 a 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 the 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 [answer1].  On the average, 2.0 [answer2] miles per gallon was achieved with regular gas.  When using the paired t procedure, we [answer3] successful in reducing variation between the types of gasoline, because the standard deviation for the differences: sd = [answer4] miles per gallon is [answer5] the standard deviations found with the original two samples for Premium and Regular gas.

A randomly selected sample of n = 20 activity monitor/ tracker users completed a survey. These activity monitor/ tracker users indicated that they walked on average 8,000 steps per day with a standard deviation of 90 steps per day. The calculated standard error of the mean is 20.1 steps per day. Assume that all conditions are met to use the theoretical t distribution for inference.  Which is correct 98% confidence interval for the average number of steps walked per day by activity monitor/tracker users?

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 [answer1].  On the average, 2.0 [answer2] miles per gallon was achieved with premium gas.  When using the paired t procedure, we [answer3] successful in reducing variation between the types of gasoline, because the standard deviation for the differences: sd = [answer4] miles per gallon is [answer5] the standard deviations found with the original two samples for Premium and Regular gas.

A researcher uses a sample of 140 Labrador service dogs in training to conduct a chi-square test for association between two variables: coat color (yellow, black, chocolate), and whether success was achieved with completion of the service dog training program  (yes, no).  After calculating the expected counts and summing the chi-square contributions, the chi-square statistic is equal to 3.01. Which figure below correctly shows the p-value for this test?

Consider each of the samples below and determine whether or not conditions are met to use a t-distribution for inference about the population mean. A.   B. C. D.  

Researchers test the provided hypotheses about two variables: ‘Favorite type of Apple’ (Red Delicious, Granny Smith, Honeycrisp, Empire, Gala) and ‘Time Aone where you Live: ‘(Pacific, Mountain, Central, Eastern) when based on a sample of n = 2000 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 0.0246.  What is the correct conclusion for this hypothesis test using a significance level of 0.05?

A  study considered the following two variables: 1. How many times went to the dentist in the past year: never or twice 2. Have a cavity:  no    yes     no yes total never 44  3  47 twice 49  4  53 total 93  7  100 Match the statistic to its corresponding calculation

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 [answer1] = [answer2] or any value [answer3] is [answer4], if in fact the [answer5] hypothesis is true.

Researchers surveyed n = 25 stat 200 female students to determine how many days out of the week they consume one or more alcoholic beverage. Their goal was to see if there was evidence that females students in stat 200 had consumed alcoholic beverages more than 2 days per week, on the average. The relevant sample statistic is 2.30 days per week with a standard error of 0.332 days per week.  The p-value is 0.188. Correctly complete the p-value interpretation below: The chance of seeing a test statistic of [answer1] = [answer2] or any value [answer3] is [answer4], if in fact the [answer5] hypothesis is true.

:Assume a researcher asks 125 Penn State students the following two questions   How do you typically commute to class from your home? (walk, bike, take bus, drive) Are you an only child?  (yes, no) The responses are summarized below. Yes    No    Total Walk 25 35 60 Bike 6 12 18 Take the bus 4 18 22 Drive 10 15 25 Total 45 80 125 When considering ‘Yes’ and ‘Bike’,  the correct calculation for the expected count is [answer1]. The correct interpretation of the expected count is: If the two variables are [answer2], we would expect that around [answer3] of children who [answer4] an “only child” to [answer5] when commuting from home to class.