Quantitative Methods

The correlation coefficient ranges between

-1 and +1.

The median of a sample will always equal the

50th percentile.

The standard deviation of a sample of 81 observations equals 49. The variance of the sample equals

6561.

The empirical rule states that, for data having a bell-shaped distribution, the percentage of data values being within one standard deviation of the mean is approximately

68%.

Statements about the proportion of data values that must be within a specified number of standard deviations of the mean can be made using

Chebyshev's theorem.

The percentage of data values that must be within one, two, and three standard deviations of the mean for data having a bell-shaped distribution can be determined using

The empirical rule.

Which of the following is not a measure of variability?

The midrange

An unusually small or unusually large data value is called

an outlier.

The mean of the sample Correct Answer

can assume any value between the highest and the lowest value in the sample.

From a population of size 1,000, a random sample of 100 items is selected. The mean of the sample

can be larger, smaller or equal to the mean of the population.

From a population of size 500, a random sample of 50 items is selected. The mode of the sample

can be larger, smaller or equal to the mode of the population.

The coefficient of correlation

cannot be larger than 1.

A numerical measure of linear association between two variables is the

covariance.

When n - 1 is used in the denominator to compute variance, the data set

is a sample.

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

is the average value of the two middle items when all items are arranged in ascending order.

The measure of location which is the most likely to be influenced by extreme values in the data set is the

mean.

The 50th percentile is the

median.

The most frequently occurring value of a data set is called the

mode.

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

must be at least zero.

The numerical value of the standard deviation can never be

negative.

The pth percentile is a value such that approximately

p percent of the observations are less than the value and (100 - p) percent are more than this value.

When the data are skewed to the right, the measure of Skewness will be

positive.

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

range.

Which of the following is not a measure of central location?

standard deviation

A numerical value used as a summary measure for a sample is known as a sample

statistic.

Which of the following symbols represents the mean of the population?

u

Which of the following symbols represents the mean of the sample?

x ¯

The __________ can be interpreted as the number of standard deviations a data value is from the mean of all the data values.

z-score

Which of the following symbols represents the standard deviation of the population?

σ

Which of the following symbols represents the variance of the population?

σ 2