Drawing Inferences from Data

The dot plots show how long it took students in Mr. Chauncey's two science classes to finish their science homework last night. Find the means to make an inference about the data.

• The 1st period mean is 35. The 2nd period mean is 38.75. On average, it took students in the 1st period class slightly longer to finish their homework than it did the students in the 2nd period class.

• The 1st period mean is 38.75. The 2nd period mean is 35. On average, it took students in the 1st period class slightly longer to finish their homework than it did the students in the 2nd period class.

• The 1st period mean is 35. The 2nd period mean is 38.75. On average, it took students in the 2nd period class slightly longer to finish their homework than it did the students in the 1st period class.

• The 1st period mean is 38.75. The 2nd period mean is 35. On average, it took students in the 2nd period class slightly longer to finish their homework than it did the students in the 1st period class.

The dot plot shows a random sample of the number of fish caught and released by 30 participants during a two-day fishing tournament. Select the inference that can be made based on the data collected.

• On average, most participants caught and released 5 or more fish.

• More participants caught 6 fish than any other number.

• The same participants who caught and released 1 fish the first day caught and released 1 fish on the second day.

• On average, participants caught and released more fish on Day 2.

If you compare the medians of each data set, who spends more time online?

• Seventh graders

• Eight graders

• Both grades spend an equal amount of time online.

• Impossible to determine form the data sets.

In an effort to try to convince her mother that she is too old to join the intermediate swim​ class, Mira, who is 13 years​ old, gathers data on the ages of a random sample of members of the current intermediate swim class. The results of the data collected by Mira are displayed in the dot plot shown.

• It is likely that she will be able to convince her mother.​ Mira's age is within the area where the data are clustered.

• It is likely that she will be able to convince her mother.​ Mira's age is to the left of the area where the data are clustered.

• It is unlikely that she will be able to convince her mother.​ Mira's age is within the area where the data are clustered.

• It is unlikely that she will be able to convince her mother.​ Mira's age is to the left of the area where the data are clustered.

A travel club has 3,000 members. A random sample of 50 of the club members found that 12 people like mountain vacations best. Which statement is NOT supported by the sample data?

• Twenty-four percent of those sampled say they like mountain vacations best.

• An estimated 720 club members would likely say they enjoy mountain vacations best.

• Almost one-quarter of club members would likely say they enjoy mountain vacations best.

• More than 2,500 club members would likely say they prefer other vacations over mountain vacations.

What inference can you draw from this survey?

• I can infer that most students in this school like pizza.

• I can infer that very few students like hamburgers.

• I can infer that their favorite is corn dogs.

• I can infer that most students in this school like hamburgers.

Litzy collects data from a random sample of 7th graders. Out of 40 respondents, 7 attend afterschool programs. Of the 200 7th graders attending Litzy's school, how many would be expected to attend afterschool programs?

• 14 7th graders

• 28 7th graders

• 35 7th graders

• 42 7th graders

The following dot plots show the amount of time it takes each​ person, in a random​ sample, to complete two similar problems. Make a comparative inference about the two problems.

• The problems are equally challenging.

• Problem 2 is more difficult because it took students longer on average.

• Problem 1 is more difficult because it took students longer on average.

The following shows the number of calls two radio shows get each day for a ten day period. The two shows are on at the same time. Make a comparative inference based on the median values.

• Show 1 usually receives more calls.

• Show 2 usually receives more calls.

• The shows usually receive equal numbers of calls.

• There is not enough data to draw an inference.

A random survey of 7th graders finds that 7 out of 10 have more than 1 hour of screen time each day. If there are 110 7th graders in your school, how many would you expect to have more than 1 hour of screen time?

• 77

• 70

• 75

• 81