Stat Quiz

1. In the graph, there are two distributions: A and B. We can know from the graph:

a. Distribution A has a bigger standard deviation than distribution B

b. Distribution B has a bigger standard deviation than distribution A

c. Distribution A and distribution B have the same standard deviation

d. We cannot tell which has a larger standard deviation from the graph

2. A researcher collected BMI (Body Mass Index) of 50 students in an Engineering school. He found the mean BMI was much smaller than the median BMI. The reason for this might be___

a. Several students had much smaller BMI scores than the other students

b. Several students had much larger BMI scores than the rest

c. The researcher made some measurement errors

d. All the students had smaller BMI scores, compared to national average

3. What is the level of measure for each of the following:

a) Final grades in this class _____________________

b) Weights of newborn babies _____________________

c) Seasons of the year _____________________

d) Boiling temperatures of different liquids _____________________

4. Determine type of sampling used:

a) I collected shoe sizes from my family _____________________

b) 1003 adults were called after their phone

numbers were randomly generated by computer ____________________

c) Police stopped every sixth driver for sobriety test ____________________

d) U.S.D.O.C. collected data by randomly selecting

8 Federal prisons and surveying every prisoner _____________________

5. I collected radon samples from basements in my neighborhood and obtained the following:

Identify class width ______________________

Identify class midpoints ______________________

Identify class boundaries ______________________

Create a histogram for these data.

6. Create a scatterplot of car weights and braking distance using the data below. Based on the result, does there appear to be a relationship between weight of a car and its braking distance?

7. The weekly salaries for teachers of the different grades at my school are as follows:

Calculate the standard deviation. Do the different grades have much variation in salary?

8. A simple random sample of pages of my dictionary was collected. These are the number of words defined on each page. Find the mean, median, mode, and midrange.

51 63 36 43 34 62 73 39 53 79

There are 1459 pages. Estimate the total number of words in the dictionary. Is the estimate likely to be an accurate estimate of the total number of words in the English language?

9. I had 10 students last term who earned the following grades:

98 85 89 73 76 85 87 92 85 56

Find the first quartile: ________________

Find the median: ________________

Find the third quartile:________________

Find the interquartile:_________________