Unit 1 Stats review

10. At a photography contest, entries are scored on a scale from 1 to 100. At a recent contest with 1,000 entries, a score of 68 was the 77th percentile of the distribution of all the scores. Which of the following is the best description of the 77th percentile of the distribution?

A. There were 770 entries with a score less than or equal to 68.

9.A statistician at a metal manufacturing plant is sampling the thickness of metal plates. If an outlier occurs within a particular sample, the statistician must check the configuration of the machine, The distribution of metal thickness has mean 23.4 mm and standard deviation 1.4 mm. Based on the two-standard deviations rule for outliers, of the following, which is the greatest thickness that would require the statistician to check the configuration of the machine?

B. 20.6

5. Roger claims that the two statistics most likely to change greatly when an outlier is added to a small data set are the mean and the median. Is Roger's claim correct?

B. No, only the mean is likely to change greatly

1. A market researcher asked a group of men and women to choose their fav color design from a sample of advertisements. The results are shown in the following table. Which of the following statements is NOT supported by the table?

C. For men, the number who chose a design with black was greater than the number who chose a design with blue.

8. The following histogram shows the ages in years, of the people who attended a documentary at a movie theater. Based on the histogram, which of the following statements best describes the relationship between the mean and the median of the distribution of ages?

C. The mean is most likely less than the median because the distribution is skewed to the left.

2. At a small coffee shop, the distribution of the number of seconds it takes for a cashier to process an order is approx. normal with the mean 276 seconds and standard deviation of 38 seconds. Which of the following is closest to the proportion of orders that are processed in less than 240 secs?

E. 0.95

4. One statistic calculated for pitchers in baseball is called the earned run average, or ERA. The following boxplots summarize the ERA for pitchers in two leagues, A and B. Based on the boxplots, which of the following statistics is the same for both leagues?

B. The interquartile range.

7. One way to measure the duration of subterranean disturbances such 7. One way to measure the duration of subterranean disturbances such as earthquakes and mining is to calculate the root-mean-square time. The following histograms summarize the distributions of the root-mean-square times for two sources of disturbances. Based on the histograms, which of the following correctly compares the 2 disturbances?as earthquakes and mining is to calculate the root-mean-square time. The following histograms summarize the distributions of the root-mean-square times for two sources of disturbances. Based on the histograms, which of the following correctly compares the 2 disturbances?

B. The median of the earthquake disturbances is less than the median of the mining disturbances.

6. The following boxplot shows the typical gas mileage, in miles per gallon, for 20 diff car models. Based on the boxplot, the top 25% of the cars have a typical gas mileage of at least how many miles per gallon?

D. 35

12. The following boxplot summarizes the heights of a sample of 100 trees growing on a tree farm. Emily claims that a tree height of 43 inches is an outlier for the distribution. Based on the 1.5 x IQR rule for outliers, is there evidence to support the claim?

D. No, because 43 is not greater than (Q3 + 1.5 x IQR)

The following list shows the number of video games sold at a game store each day for one week. 15, 43, 50, 39, 22, 16, 20 Which of the following is the best classification of the data in the list?

D. quantitative and discrete

11.A sample of 100 students from Liberty HS and a sample of 60 students from Central HS were asked what they planned to do after graduation. Responses fell into 5 categories: four-year university, community college, join the workforce, join the military, or undecided. Which statement is supported by the bar chart?

E. For the category undecided, the number of students from Liberty HS was 4 greater than the number of students from Central HS

3. In a certain school district, students from grade 6 through 12 can participate in a school-sponsored community service activity. The following bar chart shows the relative frequencies of students from each grade who participate in the community activity. Which of the following statements is supported by the bar chart?

E. Grade 11 had the greatest relative frequency of participating students