BAN ags

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

F

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. True False

F

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

F, mean affected

Geometric Mean

Finding the average rate of return over time

The three commonly used graphic forms are:

HistogramsFrequency polygonsCumulative frequency distributions

Advantage of the histogram:

It depicts each class as a rectangle, with the height of the rectangular bar representing the number in each class.

Mean

It requires the interval scale. • Major characteristics:- All values are used.- It is unique.- The sum of the deviations from the mean is 0.- It is calculated by summing the values and dividing by the number of values.

Types of variables

Qualitative Quantitative

Four Levels of Management

Ratio level, Nominal level, Ordinal level, Interval level

Variable

Something that varies.A factor, phenomenon, or characteristic that has more than one value or category.

MODE

The value of the observation that appears most frequently.

Qualitative

the characteristic being studied is nonnumeric ex Gender, religious affiliation, type of automobile owned, state of birth, eye color

Ratio level

the interval level with an inherent zero starting point. Differences and ratios are meaningful for this level of measurement. EXAMPLES: monthly income of surgeons, or distance traveled by manufacturer's representatives per month

A population is a collection of all individuals, objects, or measurements of interest.i

true

What is Statistics?

"The science of collecting, organizing, presenting, and interpreting data to assist in making more effective decisions."

Practice of statistics should be based on integrity and honesty when:

1.Collecting data2.Analyzing data3.Reporting results and conclusions based on the data

The main purpose of descriptive statistics is to: A. Summarize data in a useful and informative manner. B. Make inferences about a population. C. Determine if the data adequately represents the population. D. Gather or collect data.

A

The names of the positions in a corporation, such as chief operating officer or controller, are examples of what type of variable? A. Qualitative B. Quantitative C. Interval D. Ratio

A

What type of chart should be used to show relative class frequencies? A. A pie chart B. A bar chart C. A histogram D. A frequency polygon

A

Which of the following is an example of a continuous variable? A. Tons of concrete to complete a parking garage B. Number of students in a statistics class C. Zip codes of shoppers D. Rankings of baseball teams in a league

A

PIE CHART

A chart that shows the proportion or percent that each class represents of the total number of frequencies.

Inferential Statistics

A decision, estimate, prediction, or generalization about a population based on a sample.

HISTOGRAM

A graph in which the classes are marked on the horizontal axis and the class frequencies on the vertical axis. The class frequencies are represented by the heights of the bars and the bars are drawn adjacent to each other.

BAR CHART

A graph that shows qualitative classes on the horizontal axis and the class frequencies on the vertical axis. The class frequencies are proportional to the heights of the bars.

FREQUENCY TABLE

A grouping of qualitative data into mutually exclusive and collectively exhaustive classes showing the number of observations in each class.

FREQUENCY DISTRIBUTION

A grouping of quantitative data into mutually exclusive and collectively exhaustive classes showing the number of observations in each class.

STATISTIC

A measurable characteristic of a sample.

Dispersion

A measure of location, such as the mean or the median, only describes the center of the data but it does not tell us anything about the spread of the data.

What type of chart should be used to describe the frequency table? A. A pie chart B. A bar chart C. A histogram D. A frequency polygon

B

For a relative frequency distribution, relative frequency is computed as _____________. A. The class width divided by the class interval B. The class midpoint divided by the class frequency C. The class frequency divided by the class interval D. The class frequency divided by the total frequency

D

For any data set, which measures of central location have only one value? A. Mode and median B. Mode and mean C. Mode and standard deviation D. Mean and median

D

Types of Statistics

Descriptive and Inferential Statistics

Advantage of the frequency polygon:

It allows us to compare directly two or more frequency distributions.

VARIANCE

The arithmetic mean of the squared deviations from the mean.

Class interval

The class interval is obtained by subtracting the lower limit of a class from the lower limit of the next class

Class frequency

The number of observations in each class.

STANDARD DEVIATION

The square root of the variance.

A relative frequency captures the relationship between

a class total and the total number of observations.

sample

a portion, or part, of the population of interest.

most widely used measure of location.

arithmetic mean

According to Chebyshev's theorem, at least what percent of the observations lie within plus and minus 1.75 standard deviations of the mean? A. 56%B. 95%C. 67%D. 100%

c

A frequency polygon

similar to a histogram, also shows the shape of a distribution. It consists of line segments connecting the class midpoints of the class frequencies.

Interval level

similar to the ordinal level, with the additional property that meaningful amounts of differences between data values can be determined. There is no natural zero point. EXAMPLE: temperature on the Fahrenheit scale

Continuous variables

can assume any value within a specified range. EXAMPLE: the pressure in a tire, the weight of a pork chop, or the height of students in a class

Discrete variables

can only assume certain values and there are usually "gaps" between values. EXAMPLE: the number of bedrooms in a house or the number of hammers sold at the local Home Depot (1,2,3,...,etc.

If something has only one value, then it is a

constant

Ordinal level

data arranged in some order, but the differences between data values cannot be determined or are meaninglessEXAMPLE: During a taste test of 4 soft drinks, Mellow Yellow was ranked number 1, Sprite number 2, Seven-up number 3, and Orange Crush number 4. high, medium, low)

Nominal level

data that is classified into categories and cannot be arranged in any particular orderEXAMPLES: eye color, gender, religious affiliation

Quantitative Variables - Classifications

discrete or continuous

Descriptive statistics are used to find out something about a population based on a sample.

false

The ordinal level of measurement is considered the "lowest" level of measurement. True False

false

The terms descriptive statistics and inferential statistics can be used interchangeably. True False

false

If we select 100 persons from 25,000 registered voters and question them about candidates and issues, the 100 persons are referred to as the population.

false its sample

MEDIAN

he midpoint of the values after they have been ordered from the minimum to the maximum values.

Quantitative

information is reported numerically EXAMPLES: balance in your checking account, minutes remaining in class, or number of children in a family

population

is a collection of all possible individuals, objects, or measurements of interest.

population mean

is the sum of all the population values divided by the total number of population

PARAMETER

measurable characteristic of a population.

Descriptive Statistics

methods of organizing, summarizing, and presenting data in an informative way

Class midpoint:

point that divides a class into two equal parts. This is the average of the upper and lower class limits.

Which one of the following is referred to as the population mean? A. μ B. s C. σ D. 𝑥

population means Greek letter***** A

Class frequencies can be converted to ______________ to show the fraction of the total number of observations in each class.

relative class frequencies