CHAPTER 3 QUIZ

According to the Empirical rule, about 95% of the observations lie within plus and minus two standard deviations of the mean.

True

For any data set, Chebyshev's theorem estimates the proportion of the values that lie within k standard deviations of the mean, where k is greater than 1.0.

True

Ten people are sampled. Three (3) of them earn $8 an hour, six (6) of them earn $9 an hour, and one (1) of them earns $12 an hour. The weighted mean of the hourly wages is $9

True

The arithmetic mean is calculated as the sum of the values, divided by the total number of values observed.

True

The mode is the value of the observation that appears most frequently.

True

The standard deviation is the square root of the variance.

True

The sum of the deviations of each value (For example: 4, 9, and 5) from the mean of those values, is zero.

True

A set of ordinal-, interval-, or ratio-level data may have only one mode.

False

Extremely high or low scores affect the value of the median.

False

For a set of data arranged or sorted in numerical order, the value of the observation in the center is called the weighted mean.

False

In a company, the standard deviation of the ages of female employees is 6 years and the standard deviation of the ages of male employees is 10 years. These statistics indicate that the dispersion of age is greater for females than for males.

False

The variance is the arithmetic mean of the squared deviations from the median.

False