Stats Concepts

In a survey of men in the United States (ages 20-29), the mean height was 69.6 inches with a standard deviation of 3.0 inches. Find the minimum height in the top 22%.

• 69.37 in 

• 67.58 in 

• 73.12 in 

The mean number of accidents a week at a company is 6.4 with a standard deviation of 1.5.  What proportion of weeks would you expect to have less than 5 accidents?

• 0.6915

• 0.1762

• 0.8238

• -0.93

The average waist size for teenage males is 29 inches with a standard deviation of 1.4 inch. 
If waist sizes are normally distributed, estimate the proportion of teenagers who will have waist   sizes greater than 31 inches?

• 92.4%

• 10.5%

• 16%

• 7.6%

The scoring of modern IQ is such that Intelligence Quotients (IQs) have a normal distribution of μ= 100 and 𝞂 = 15.

Mensa International is a non-profit organization that accepts only people with IQ score within the top 2%. What level of IQ qualifies one to be a member of Mensa?

• 115

• 130.75

• 145

• 120

The distances male long jumpers for State College jump are approximately normal with a mean of 263 inches and a standard deviation of 14 inches.  
Suppose a male long jumper's jump ranked in the 75th percentile.  How long was his jump?

• 0.67 inch

• 263 inches

• 272.44 inches

• 277.25 inches

Women’s heights have a mean of 63.6 in. and a standard deviation of 2.5 inches.  The z score corresponding to a woman with a height is 2.56. How tall is the woman?

• 24.42 in

• 70 in

• 28in

• 68.6in

The percentile represents the....

• percent of data values that are below.

• percent of data values that are above.

• number of data values that are below.

• number of data values that are below.

Which measure of center is most affected by an outlier?

• mean

• median

• mode

• standard deviation

• interquartile range

If 20 is added to every number in a data set, which statement will be true?

• The median will stay the same, but the IQR will increase by 20.

• The median will increase by 20, but the IQR will stay the same.

• Both the median and the IQR will increase by 20.

• Both the median and the IQR will stay the same.

If the data points are changed to different units by multiplying each number in the data set, which statement will be true?

• The median will stay the same, but the IQR will change.

• The median will change, but the IQR will stay the same.

• Both the median and the IQR will change.

• Both the median and the IQR will stay the same.