# stat 2and 3

## 99 terms

### number of items in several classes

A frequency distribution is a tabular summary of data showing the

### a tabular summary of a set of data showing the frequency of items in each of several nonoverlapping classes

A frequency distribution is

### relative frequency distribution

A tabular summary of a set of data showing the fraction of the total number of items in several classes is a

### dividing the frequency of the class by the sample size

The relative frequency of a class is computed by

### multiplying the relative frequency by 100

The percent frequency of a class is computed by

### the number of elements in a data set

The sum of frequencies for all classes will always equal

### both a bar graph and a pie chart

Fifteen percent of the students in a school of Business Administration are majoring in Economics, 20% in Finance, 35% in Management, and 30% in Accounting. The graphical device(s) which can be used to present these data is (are)

### qualitative data

A researcher is gathering data from four geographical areas designated: South = 1; North = 2; East = 3; West = 4. The designated geographical regions represent

### bar graph

Qualitative data can be graphically represented by using a(n)

### the proportion of data items with values less than or equal to the upper limit of each class

A cumulative relative frequency distribution shows

### fewest classes

If several frequency distributions are constructed from the same data set, the distribution with the widest class width will have the

### one

The sum of the relative frequencies for all classes will always equal

### 100

The sum of the percent frequencies for all classes will always equal

### histogram The most common graphical presentation of quantitative data is a

The most common graphical presentation of quantitative data is a

### cumulative frequency distribution

The total number of data items with a value less than the upper limit for the class is given by the

### dividing the frequency of the class by n

The relative frequency of a class is computed by

### (largest data value - smallest data value)/number of classes

In constructing a frequency distribution, the approximate class width is computed as

### increases

In constructing a frequency distribution, as the number of classes are decreased, the class width

### class width

The difference between the lower class limits of adjacent classes provides the

### the total number of elements in the data set

In a cumulative frequency distribution, the last class will always have a cumulative frequency equal to

### one

In a cumulative relative frequency distribution, the last class will have a cumulative relative frequency equal to

### 100

In a cumulative percent frequency distribution, the last class will have a cumulative percent frequency equal to

### qualitative data

Data that provide labels or names for categories of like items are known as

### crosstabulation

A tabular method that can be used to summarize the data on two variables simultaneously is called

### a scatter diagram

A graphical presentation of the relationship between two variables is

### longer tail to the left

A histogram is said to be skewed to the left if it has a

### skewed to the right

When a histogram has a longer tail to the right, it is said to be

### trend line

In a scatter diagram, a line that provides an approximation of the relationship between the variables is known as

### graphical presentation of a frequency or relative frequency distribution

A histogram is

A situation in which conclusions based upon aggregated crosstabulation are different from unaggregated crosstabulation is known as

### mean

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

### mean

The most important statistical descriptive measure of the location of a data set is the

### None of these alternatives is correct

If two groups of numbers have the same mean, then

### None of these alternatives is correct.

The mean of the sample

### the trimmed mean

When the smallest and largest percentage of items are removed from a data set and the mean is computed, the mean of the remaining data is

### could be larger, equal to, or smaller than the true value of the population mean

Since the population is always larger than the sample, the value of the sample mean

### mean

Which of the following provides a measure of central location for the data?

### can be any value

When computing the mean of a set of values xi, the value of xi

### n

In computing the mean of a sample, the value of xi is divided by

### sample statistic

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

### can be smaller, larger, or equal to the population parameter

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

### population parameter

 is an example of a

### is computed by summing all the data values and dividing the sum by the number of items

The mean of a sample

### The coefficient of variation equals ANS: 30%

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

### 24

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

### 50th percentile

The median of a sample will always equal the

### central location

The median is a measure of

### median

The 50th percentile is the

### third quartile

The 75th percentile is referred to as the

### less than or equal to this value

The pth percentile is a value such that at least p percent of the observations are

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

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

### is the same as the 25th percentile

The rangefirst quartile

### can be any value

When computing the mean, the smallest value

### variance

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

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

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

### interquartile range

Which of the following is a measure of dispersion

### median

The value which has half of the observations above it and half the observations below it is called th

### mode

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

### he difference between the third quartile and the first quartile

The interquartile range is

### 11.25%

The weights (in pounds) of a sample of 36 individuals were recorded and the following statistics were calculated.

### 40%

The heights (in inches) of 25 individuals were recorded and the following statistics were calculated

mean = 70 range = 20
mode = 73

### rounded up

If index i (which is used to determine the location of the pth percentile) is not an integer, its value should be

### positive

When the data are skewed to the right, the measure of Skewness w

### greater than the median

When data are positively skewed, the mean will usually be

### the 50th percentile

Which of the following is not a measure of dispersion?

### the range is influenced too much by extreme values

The interquartile range is used as a measure of variability to overcome

### the data set is a sample

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?

### data values are treated as if they occur at the midpoint of a class

In computing descriptive statistics from grouped data,

### the range

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

### only when individual data values are unavailable

When should measures of location and dispersion be computed from grouped data rather than from individual data values?

### the standard deviation

The descriptive measure of dispersion that is based on the concept of a deviation about the mean is

### negative

The numerical value of the standard deviation can never be

### could be smaller, equal to, or larger than the true value of the population variance

The sample variance

### the standard deviation divided by the mean times 100

The coefficient of variation is

### negative

The variance can never be

### equal to zero

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

### TRIANGLE

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

### DIagnal arrow

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

### N

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

### x

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

### n

Which of the following symbols represents the size of the sample

### can never be negative

The variance of the sample

### variance

The measure of dispersion which is not measured in the same units as the original data is the

### covariance

A numerical measure of linear association between two variables is the

### positive relation between the independent and the dependent variables

Positive values of covariance indicate

### correlation coefficient

A numerical measure of linear association between two variables is the

### -1 and +1

The coefficient of correlation ranges between

### cannot be larger than 1

The coefficient of correlation

### zero

The value of the sum of the deviations from the mean, i.e., must always be

### can be larger or smaller than the numerical value of the standard deviation

The numerical value of the variance

### None of these alternatives is correct.

Since the median is the middle value of a data set it

### the mean

In a five number summary, which of the following is not used for data summarization?

### dividing the frequency of the class by the sample size

The relative frequency of a class is computed by

### must be at least zero

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

### mode

Which of the following is not a measure of dispersion?

### 784

If the coefficient of variation is 40% and the mean is 70, then the variance is

### 12.5

Given the following information:

Standard deviation = 8
Coefficient of variation = 64%

The mean would then be

### none correct

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

### 22

A group of students had dinner at a local restaurant. The total bill for the dinner was \$414.70. Each student paid his/her equal share of the bill, which was \$18.85. How many student's were at the dinner?

Example: