REVIEW: Descriptive Statistics (Fast)

The cost of five homes in a certain area is given.
$147,000
$155,000
$175,000
$145,000
$1,225,000
Which measure of central tendency should be used?

• Mean
• Median
• Mode
• Midrange

For the given data, which best describes the shape of the distribution? (Mean = 5.93, Median = 7)

• Skewed Right

• Skewed Left

• Roughly Symmetric

• Uniform

Given the following statistics about scores on the last math test, what is the best description of the shape of the distribution?

Mean: = 78

Standard Deviation = 4

Min = 64

Median = 78

Q1 = 72

Q3 = 84

Max = 99

• Skewed Right

• Skewed Left

• Roughly Symmetric

• Uniform

A statistician has computed some data on the ages of people when they have their first child. The data showed the ages to be skewed right. Which of the following is the best way to describe the central tendency (typical value)?

• Mean
• Median
• Mode
• Midrange

Given one or more of the following scenarios when might a stem-and-leaf plot be appropriate?

i. A teacher wants to see a graphical display of her class test scores.

ii. A music artist wants to see the percentages of people that buy her album by age groups (pre-teen, teen, twenties, thirties, forty and above).

iii. A guidance counselor needs to see the ACT scores of all juniors and seniors separate, but also needs the actual score values.

• i only

• ii only

• i and iii

• i, ii, iii

The dotplot shows the total number of appointments per week for 60 weeks at a local hair salon. Which of the following statements might be TRUE about the number of appointments per week?

• The median number of appointments is 50 per week with an interquartile range (IQR) of 18.5.

• The median number of appointments is 50 per week with a range of 50.

• More than half of the weeks have no more than 50 appointments per week.

• The interquartile range (IQR) cannot be determined from the dotplot above.

The distribution of the heights of the 50 highest mountains in Statland has an average of 206 meters and a standard deviation of 35 meters. Starnes Mountain has a height of 221 meters. Tyson and Tabor Mountains have z-scores of 2.69 and –1.13 respectively. Which of the following statements are true?

i. Bassed off z-scores, Starnes is taller than Tabor and Devore.

ii. Based off z-scores, Starnes is taller than Devore but shorter than Tabor.

iii. Based off z-scores, Starnes is shorter than both Tyson and Tabor.

iv. Based off z-scores, Starnes is closer to average than Tyson and Tabor.

• ii

• ii, iv

• iii

• i, ii, iii, iv

For the stem-and-leaf plot above, what is the maximum and what is the minimum entry?

• Max: 17.0; Min: 11.6

• Max: 170; Min: 116

• Max: 17.3; Min: 11.6

• Max: 17.3; Min: 11.7

For the given Ogive (above) what is approximately the cumulative frequency for 75 minutes?

• 5

• 10

• 15

• 20

The weight of apples selected at random from a bin at the local farmers market is a random variable with mean m = 12 ounces and standard deviation s = 1 ounce. If 5 apples were selected what would the expected weight and standard deviation of all 5 apples together?

• Mean of 12 ounces with a standard deviation of 1 ounce.

• Mean of 60 ounces with a standard deviation of 5 ounces.

• Mean of 60 ounces with a standard deviation of 2.236 ounces.

• Mean of 12 ounces with a standard deviation of 2.236 ounces.