Chapter 04 Quiz (with video solutions)

The following are the grades a professor gave on the first test in a statistics
class: 52, 90, 88, 61, 75, 82, 75, 83, 88, and 86.

What was the median score on this test?

A clothes store manager has sales data of trouser sizes for the last month’s
sales. Which measure of central tendency should the manager use, if the
manager is interested in the most sellable size?

What measure of central tendency is most sensitive to skewness?

The number of bottles filled each day in a bottling plant is observed for a
week: 674, 589, 613, 689, 554, 586, and 594. What was the mean?

The number of bottles filled each day in a bottling plant is observed for a
week: 674, 589, 613, 689, 554, 586, and 594. What was the standard
deviation?

If a given distribution is known to be bell-shaped and symmetric, what percent
of the observations are expected to fall within two standard deviations of the
mean?

The only legitimate measure of central tendency for nominal scale data
distributions is the:

The mean is ________ an inappropriate measure of central tendency or most
typical value for ordinal data.

Since the population size is always larger than the sample size, then the
sample statistic

The hourly wages of a sample of 130 system analysts are given below.
mean = 60         range = 20
mode = 73         variance = 324
median = 74

The coefficient of variation equals

The variance of a sample of 169 observations equals 576. The standard
deviation of the sample equals

The difference between the largest and the smallest data values is the

If a data set has an even number of observations, the median

When data are positively skewed, the mean will usually be

If the variance of a data set is correctly computed with the formula using n – 1
in the denominator, which of the following is true?

The measure of dispersion that is influenced most by extreme values is

The numerical value of the standard deviation can never be

If two groups of numbers have the same mean, then

The sum of deviations of the individual data elements from their mean is

A numerical measure of linear association between two variables is the

Positive values of covariance indicate

The coefficient of correlation ranges between

During a cold winter, the temperature stayed below zero for ten days (ranging
from -20 to -5). The variance of the temperatures of the ten day period

Since the mode is the most frequently occurring data value, it

This set of data represents the average rainfall (measured as inches) in June
at the Statsville airport for the past 10 summers:

        0.7, 1.6, 4.1, 0.7, 0.7, 3.3, 2.4, 1.6, 0.1

If the largest and smallest observed values were removed, in what way
would the mean, median and mode be affected?

If a data set is approximately bell-shaped with µ = 40 and σ = 8, the
values between 24 and 48 will consisit of what percent of the data?

The length of baseball games is approximately normally distributed with a
mean of 2.45 hours. Using the Empirical Rule, about 95% of baseball games
take between 1.71 and 3.19 hours to play. The standard deviation is