The dotplot displays the total number of miles that the 28 residents of one street in a certain community traveled to work in one five-day workweek. Which of the following is closest to the percentile rank of a resident from this street who traveled 85 miles to work that week?

• 60

• 70

• 75

• 80

• 85

A large SRS of people aged 19 to 30 living in the state of Colorado was surveyed to determine which of two MP3 players just developed by a new company was preferred. To which of the following populations can the results of this survey be safely generalized?

• Only people aged 19 to 30 living in Colorado who were in this survey.

• Only people aged 19 to 30 living in Colorado

• All people living in Colorado

• Only people 19 to 30 living in the United States

• All people living in the United States

Janelle collected data on the amount of time in minutes each person in a large sample of customers spent in a local store. The data also included recording the gender of each customer. These data were used to generate the boxplots. Which of the following statements is true?

• The range in the amount of time males in the sample of customers spent in the store is approximately 40 minutes.

• The mean amount of time males in the sample of customers spent in the store is approximately 20 minutes.

• The third quartile of the amount of time males in the sample of customers spent in the store is approximately 45 minutes

• The interquartile range of the amount of time males in the sample of customers spent in the store is approximately 15 minutes

• Approximately half of the males in the sample of customers spent at least as much time in the store as any female in the sample of customers.

The buyer for an electronics store wants to estimate the proportion of defective wireless game controllers in a shipment of 5,000 controllers from the store's primary supplier. The shipment consists of 200 boxes each containing 25 controllers. The buyer numbers the boxes from 1 to 200 and randomly selects six numbers in that range. She then opens the six boxes with the corresponding numbers, examines all 25 controllers in each of these boxes, and determines the proportion of the 150 controllers that are defective. What type of sample is this?

• Biased random sample

• Convenience sample

• Simple random sample

• Stratified random sample

• Cluster random sample

Which of the following scatterplots could represent a data set with a correlation coefficient of r = -1?

• 
• 
• 
• 
• 

An environmental scientist wants to test the null hypothesis that an antipollution device for cars is not effective. Under which of the following conditions would a Type I error be committed?

• The scientist concludes that the antipollution device is effective when it actually is not.

• The scientist concludes that the antipollution device is not effective when actually is.

• The scientist concludes that the antipollution device is effective when it actually is.

• The scientist concludes that the antipollution device is not effective when it actually is not.

• A Type I error cannot be committed in this situation.

A data set of test scores is being transformed by applying the following rule to each of the raw scores.

Transformed score = 3.5(raw score) + 6.2

Which of the following is NOT true?

• The mean transformed score equals 3.5(the mean raw score) + 6.2

• The median transformed score equals 3.5(the median raw score) + 6.2

• The range of the transformed scores equals 3.5(the range of the raw scores) + 6.2

• The standard deviation of the transformed scores equals 3.5(the standard deviation of the raw scores)

• The IQR of the transformed scores equals 3.5(the IQR of the raw scores)

A random sample of 25 households from the Mountainview School District was surveyed. In this survey, data were collected on the age of the youngest child living in each household. The histogram displays the data collected in the survey. In which of the following intervals is the median of these data collected?

• 0 to 2

• 4 to 6

• 6 to 8

• 8 to 10

• 10 to 12

In a random sample of 60 shoppers chosen from the shoppers at a large mall, 36 indicated that they had been to a movie in the past month. In an independent random sample of 50 shoppers chosen from the shoppers in the downtown shopping area, 31 indicated that they had been to a movie in the past month. What significance test should be used to determine whether these data provide sufficient evidence to reject the hypothesis that the proportion of shoppers at the mall who had been to a movie in the past month is the same as the proportion of shoppers in the downtown shopping area who had been to a movie in the past month?

• One proportion z-test

• One sample z-test for a mean

• One sample t-test for a mean

• Two proportion z-test

• Two sample t-test for means

The National Honor Society at Central High School plans to sample a random group of 100 seniors from all high schools in the state to determine the average number of hours per week spent on homework. A 95 percent confidence interval for the mean number of hours spent on homework will then be constructed using the sample data. Before selecting the sample, the National Honor Society decides that it wants to decrease the margin of error. Which of the following is the best way to decrease the margin of error?

• Increase the confidence level to 99%

• Use the population standard deviation

• Use the sample standard deviation

• Decrease the sample size

• Increase the sample size