Mean Frequency Distribution AP Stat

The stem-and-leaf diagram below gives the distribution of the ages in years of 20 participants at a family reunion. Which of the following statements about the distribution is correct?

• The first quartile is larger than the third quartile.

• The distribution is strongly skewed to the left.

• It makes the most sense to use the mean and standard deviation as a numerical summary of the center and spread of this distribution.

• The mean is larger than the median.

• A

• B

• C

• D

• E

• A

• B

• C

• D

• E

Use the following information and the Empirical Rule to estimate the answer.

The ages of golfers are normally distributed, with a mean of 38 and a standard deviation of 4.

Find the percentage of golfers that are between 30 and 46 years old.

• 68%

• 94%

• 95%

• 99.7%

Find the mean, for the given distribution:

• 4.2

• 2.1

• 4

• 2

Answer explanation

Identify the class with the highest relative frequency.

• 95 - 105

• 105 - 115

• 115 - 125

• 125 - 135

Which Class has the highest frequency?

• 2.5-3.0

• 0.5-4.0

• 2.5-3.5

• 3.0-3.5

Why is this frequency distribution incorrect?

• The fourth class width is different from the others

• There is a zero.

• Classes should overlapped.

What's the probability of 49 < x < 51 ?

(Mean = 50, Standard dev = 6.5)

• 0.1192

• 0.1251

• 0.1587

• 0.0875

According to the table, what is the relative frequency of Students ages 14 - 17 who skip breakfast?

• About 27%

• About 35%

• About 15%

• About 30%