statistic cpt 3

21) What is the weighted arithmetic mean price per ton?

72.33

For an ungrouped data set with an odd number of observations that have been sorted or arrayed from smallest to largest values, where is the median located?

(n + 1)/2

The net incomes (in $ millions) of a sample of steel fabricators are: $86, $67, $86 and $85. What is the modal net income?

86

Fifteen accounting majors had an average grade of 90 on a finance exam. Seven marketing majors averaged 85, while ten finance majors averaged 93 on the same exam. What is the weighted mean for the 32 students taking the exam?

89.84

A bottling company offers three kinds of delivery service - instant, same day and within five days. The profit per delivery varies according to the kind of delivery. The profit for an instant delivery is less than the other kinds because the driver has to go directly to a grocery store with a small load and return to the bottling plant. To find out what effect each type of delivery has on the profit picture, the company summarized the data in the following table based on deliveries for the previous quarter. What is the weighted mean profit per delivery?

97

Which measure of central location is used to determine an average annual percent increase?

Geometric mean

If a frequency distribution has open-ended intervals at the extremes, which measure of central location is the most difficult to estimate?

Mean

For a data set, half of the observations are always greater than the ________ .

Median

For a symmetrical distribution, the variance is equal to the standard deviation.

false

In a positively skewed distribution, the mode is greater than the median.

false

The mean deviation is the mean of the actual values of the deviations from the arithmetic mean.

false

The variance is the mean of the sum of the squared deviations between each observation and the median

false

For which measure of central location will the sum of the deviations of each value from the data's average will always be zero?

mean

For a set of grouped or ungrouped data, which measures of central location always have only one value?

mean and median

19) What is the mean net sales (in $ millions)?

mean cannot be computed

Chebyshev's Theorem gives the proportion of observations in any data set that occurs within k standard deviations of the mean, where k is greater than 1.0.

true

The Empirical states that about 68% of the observation will lie within one standard deviation of the mean; about 95% of the observations will lie within two standard deviations of the mean; and virtually all (99.7%) will lie within three standard deviations of the mean.

true

The arithmetic mean is the sum of the observations divided by the total number of observations.

true

The geometric mean is the nth root of n observations.

true

The standard deviation is the positive square root of the variance.

true

Three persons earn $8 an hour, six earn $9 an hour, and one earns $12 an hour. The weighted mean hourly wage is $9.

true

What is the relationship among the mean, median and mode in a symmetric distribution?

They are all equal

The U.S. Federal Aviation Administration reported that passenger revenues on international flights increased from $528 million in 1983 to $5,100 million in 2006. What is the geometric mean annual percent increase in international passenger revenues?

10.4

18) What is the mean daily production

106.4

16 What is the arithmetic mean miles per gallon?

18.6

Assume a student received the following grades for the semester: History, B; Statistics, A; Spanish, C; and English, C. History and English are 5 credit hour courses, Statistics a 4 credit hour course and Spanish a 3 credit hour course. If 4 grade points are assigned for an A, 3 for a B and 2 for a C, what is the weighted mean for the semester grades?

2.61

17) What is the mean age?

26.58

What is the median of 26, 30, 24, 32, 32, 31, 27 and 29?

29.5

A sample of single persons receiving social security payments revealed these monthly benefits: $826, $699, $1,087, $880, $839 and $965. How many observations are below the median?

3

The Investment Company Institute reported in its Mutual Fund Fact Book that the number of mutual funds increased from 5725 in 1995 to 7977 in 2005. What is the geometric mean annual percent increase in the number of funds?

3.37

20. A stockbroker placed the following order for a customer: 50 shares of Kaiser Aluminum preferred at $104 a share 100 shares of GTE preferred at $25.25 a share 20 shares of Boston Edison preferred at $9.125 a share What is the weighted arithmetic mean price per share?

46.51

Production of passenger cars in Japan increased from 3.94 million in 1994 to 6.74 million in 2004. What is the geometric mean annual percent increase?

5.5

A sample of the paramedical fees charged by clinics revealed these amounts: $55, $49, $50, $45, $52 and $55. What is the median charge?

51

The lengths of time (in minutes) several underwriters took to review applications for similar insurance coverage are: 50, 230, 52 and 57. What is the median length of time required to review an application?

54.5

The number of work stoppages in a highly industrialized region for selected months are: 6, 0, 10, 14, 8 and 0. What is the median number of stoppages?

7

On a survey questionnaire, students were asked to indicate their class rank in college. If there were only four choices from which to choose, which measure(s) of central location would be appropriate to use for the data generated by that questionnaire item?

Mode and median

Which measures of central location are not affected by extremely small or extremely large values?

Mode and median

What is the lowest level of measurement that a median can be computed?

Ordinal

In the calculation of the arithmetic mean for grouped data, which value is used to represent all the values in a particular class?

The class midpoint.

Which one of the following is referred to as the population mean?

b