BSTATS Test 1
What type of variable is the number of robberies reported in your city
Discrete
The sum of the deviations form the mean for the set of numbers 3,-9 and 5 will equal one
False
There are four levels of measurement: qualitative, quantitative, discrete, and continuous
False
Which measures of centrla location always have only one value for a set of grouped or ungrouped data
Mean and median
A question in a market survey asks for a respondent's favorite car color. Which measure of central location should be used to summarize this question?
Mode
Which measures of central location are not affected by extremely small or extremely large values?
Mode and median
A small sample of computer operators shows monthly incomes of $1,950, $1,775, $2,060, $1,840, $1,795, $1,890, $1,925 and $1810 What are these ungrouped numbers called?
Raw data
What is a portion of a population called?
Sample
A simple graphical technique for studying the relationship between two variables is
Scatter plot
The main purpose of descriptive statistics is to
Summarize data in a useful and informative manner
What is the relationship among the mean, median and mode in a symmetric distribution
They are all equal
A Pareto chart can be used to differentiate the "vital few" causes of quality problems from the "trivial many" causes of quality problems
True
A box plot shows the relative symmetry of a distribution
True
A cumulative frequency distribution is used when we want to determine how many observations lie above or below certain values.
True
A frequency distribution groups data into classes showing the number of observations in each class
True
A frequency polygon is a very useful graphic technique when comparing two or more distributions
True
A line graph is a graphic that is used to display the changes in a variable over time
True
The principal difference between the interval and ratio scale is that the ratio scale has a meaningful zero point.
True
Three quartiles divide a set of data into four quarters
True
To convert a frequency distribution to a relative frequency distribution, divide each class frequency by the total sum of all class frequencies
True
The closing prices of a common stock have been 61.5, 62, 61.25, 60.875 and 61.5 for the past week. What is the range
$1.125
The net income (in $ millions) of a sample of steel fabricators are: $85, $67, and $85. What is the modal net income?
$85
The test scores for a class of 147 students are computed. What is the location of the test score associated with the third quartile
111
What is the median of 26,30,24,32,32,31,27 and 29
29.5
What is a disadvantage of the range as a measure of dispersion?
Based on only 2 observations
Sometimes, data has two values that have the highest and equal frequencies. In this case, the distribution of the data can best be described as
Bimodal (having two modes)
In a frequency distribution, what is the number of observations in a class called?
Class frequency
The relative frequency for a class is computed as
Class frequency divided by the total frequency
Which of the following is an example of attribute data
Color of ink in a pen
Which can be used to study the relationship between two attributive variables
Contingency table
What type of variable is the number of gallons of gasoline pumped by a filling station during a day?
Continuous
A relative frequency distribution shows the number of observations in each class
False
A set of ordinal, interval or ratio level data may only have one mode
False
Descriptive statistics-is used to make inferences about a population based on a sample, such as the population's average weight
False
For a set of data arranged or sorted in numerical order, the value of the observation in the center is called the weighted mean
False
For a symmetrical distribution, the variance is equal to the standard deviation
False
Ogive plot is a graph used to depict frequency or relative frequency of qualitative data
False
Pie chart is a graphical technique that places quantitative values from smallest to largest and allows us to see the shape of the dataset's distribution
False
The Union of electrical workers of America with 9,128 members polled 5,365 members regarding a new wage package to be submitted to management. The 5,365 members is the population.
False
The number of children in a family is a continuous variable
False
The order that runners finish in a race would be an example of continuous data.
False
What level of measurement are the Centigrade and Fahrenheit temperature scales
Interval
A questionnaire contained a question regarding marital status. The respondent checked single, married, divorced, separated or widowed. What is the scale of measurement for this question?
Nominal
Which of the following is an example of a discrete variable
Number of students in a statistics class
A bank asks customers to evaluate the drive-thru service as good, average, or poor. Which level of measurement is this classification
Ordinal
Stem-and-leaf displays are useful for detecting
Outliers
Which word is NOT part of the definition of descriptive statistics
Predicting
A marketing research agency was hired to test a new DVD player. Consumers rated it outstanding, very good, fair or poor. The level of measurement for this experiment is ordinal
True
A negatively skewed distribution is not symmetrical. The long tail is to the left or in the negative direction
True
A population is a collection of all individuals, objects or measurements of interest.
True
A sample is a portion or part of the the population of interest
True
A value that is typical or representative of the data is referred to as a measure of central location
True
Descriptive statistics is used to find out something about a population based on a sample, such as the population's average weight
True
Dispersion is the degree of variation in the data
True
If a variable is measured at the interval or ration level, all the values are included when computing the mean
True
Scatter plot (or diagram) is a simple graphical technique for studying the relationship between two variables
True
Statistics is defined as a body of techniques used to facilitate the collection, organization, presentation, analysis and interpretation of information for the purpose of making better decisions.
True
A graph is used to depict frequency or relative frequency of qualitative data
pie chart
