Inferences from Data

If Mr. Estes looked at the means (averages) for the last SAFE Quiz for his classes, and the averages were 81%, 82%, and 99%, what inference can you make based on those averages?

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.

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.

The table shows the results of a survey of 200 people attending a hockey game.
The attendance for the hockey game is about 25,000 visitors each game.  Based on the table, how many people out of 25,000 could be expected to buy a pennant?

• 1,375

• 1,650

• 2,750

• 3,850

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.

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.

3 of 5 doctors surveyed by a pharmaceutical company prefer their new Brand X medicine compared to the other leading brand. Is this a valid inference?

• Yes they randomly chose doctors for the survey.

• No there is no evidence that they chose the doctors for the survey at random.

• Yes they chose doctors they knew would prefer their Brand X.

• No they randomly chose doctors for the survey.

Q1. How many red shirts are there?

• A) 5 red shirts

• B) 17 red shirts

• C) 40 red shirts

• D) 83 red shirts

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