3.1 Quiz 2: descriptive statistics

The following table shows the lengths of 64 international phone calls using a $5 prepaid calling card.

Using the data, determine which ONE of the answers is correct:

• A

  The mean and the median are equal.

• B

  The mean is smaller than the median.

• C

  The mean is larger than the median.

Interpret the following box plot:

Which of the following is correct?

• A

  75% of the data are at most 5.

• B

  There is about the same amount of data from 2-5 as there is from 5-7.

• C

  There are no data values of 3.

• D

  50% of the data are 4.

In a set of data, if all of the data appear with the same frequency, then:

• A

  The standard deviation is always 0.

• B

  The mean is always larger than the standard deviation.

• C

  All of the data have the same value.

• D

  The boxplot does not always look symmetrical.

The following table shows the lengths of 64 international phone calls using a $5 prepaid calling card.

Find the 60th percentile.

• A

  14

• B

  60

• C

  15

• D

  0.2344

Consider the following data set:

• 4
• 6
• 6
• 12
• 18
• 18
• 18
• 200

What value is 2 standard deviations above the mean?

• A

  There is not enough information

• B

  Approximately -98

• C

  Approximately 102

• D

  Approximately 169

Consider the following data:

• 14
• 16
• 16
• 22
• 25
• 38
• 38
• 38
• 38
• 2000

Which of the measures of central tendency would be the least useful?

• A

  mean

• B

  mode

• C

  median

The following table shows the lengths of 64 international phone calls using a $5 prepaid calling card.

What percent of the data is either 34 or 44 minutes?

• A

  Approximately 78%

• B

  Approximately 13%

• C

  Approximately 98%

• D

  Approximately 20%

The number of responses that were either "1" or "3" is approximately:

• A

  0.4

• B

  27

• C

  40

• D

  2

Which of the following DOES NOT describe the data?

• A

  there are approximately 10 faculy members that own 7 cars

• B

  skewed left

• C

  There are no values of 5

• D

  skewed right

The third quartile is:

• A

  1

• B

  2

• C

  3

• D

  0.75