STAT: Exam 1 = Chapters 1 - 4

class midpoint

In the calculation of the arithmetic mean for grouped data, which value is used to represent all the values in a particular class?

raw data

Monthly commissions of first-year insurance brokers are $1270, $1310, $1680, $1380, $1410, $1570, $1180, and $1420. These figures are reffered to as?

2.5

What is the value of the Pearson coefficient of skewness for a distribution with a mean of 17, median of 12, and standard deviation of 6? [sk = 3(xbar - median)/s]

arithmetic mean

What measure of central location cannot be determined if the distribution has an open-ended class?

continuous

What type of variable is the number of gallons of gasoline pumped by a filling station during a day?

discrete

What type of variable is the number of robberies reported in your city?

values

When data is collected using a qualitative, nominal variable (ex. male or female), the number of classes corresponds to the number of the variable's what?

median

Which measure of central location requires that the data be ranked before it is possible to determine it?

100

a percentile divides a distribution into how many equal parts?

attribute variable

a qualitative variable such as eye color is also referred to as a(n) _____?

ratio level

the "highest" level of measurement is ______?

interquartile

the _____ range is the difference between the values of the first and third quartile, indicating the range of the middle fifty percent of the observations

Pearson's

the _______ coefficient of skewness is a measure of distribution's symmetry

coefficient of variation

the ________ is a measure of relative dispersion that expresses the standard deviation as a percent of the mean

ordinal level

ranked data is an example of what level of measurement?

odd

For an ungrouped dataset with a(n) ____ number of observations that have been sorted or arrayed from smallest to largest values, the median is located = (n+1)/2

mean

If a distribution is highly skewed, what measure of central location should be avoided?

2 to the k

If the number of observations is 124, the suggested number of classes using the "________" rule would be 7.

sample

If we test a small number of light bulbs from a large group, the small group is called a _____?

two

A frequency distribution showing the gender of a school's students would group data into how many classes?

89.84

Fifteen accounting majors had an average grade of 90 on a finance exam. (15x90 = 1350). Seven marketing major averaged 85, (7x85 = 595), while ten finance majors averaged 93 on the same exam. (10x93=930). What is the weighted mean for the 32 students taking the exam?

false

(T/F) A store asks shoppers for their zip code to identify market areas. Zip codes are an example of ratio data.

false

(T/F) For a symmetrical distribution, the variance is equal to the standard deviation.

false

(T/F) In a positively skewed distribution, the mode is greater than the median.

false

(T/F) The coefficient of variation is computed by dividing the standard deviation by the median and multiplying the quotient by 100

false

(T/F) The variance is the mean of the sum of the squared deviations between each observation and the median.

false

(T/F) a frequency distribution for qualitative data has class limits

false

(T/F) another name for inductive statistics is descriptive statistics

false

(T/F) in general, we should construct a frequency distribution so that there are either 4 or 24 classes

false

(T/F) the order that runners finish in a race would be an example of continuous data

pie chart

A ____ is similar to a relative frequency distribution

-0.75

A large oil company is studying the number of gallons of gasoline purchased per customer at self-service pumps. The means number of gallons is 10.0 with standard deviation of 3.0 gallons. The median is 10.75 gallons. What is the Pearson's coefficient of skewness? [sk = 3(xbar - median)/s]

ordinal level

A marketing research agency was hired to test a new DVD player. Consumers rated it outstanding, very good, fair or poor. This is an example of what level of measurement?

mutually exclusive

A student was interested in the cigarette smoking habits of college students and collected data from an unbiased random sample of students. The data is summarized in the following table: Male: 50 Males who smoke: 20 Males who do not smoke: 30 - Female:75 Females who smoke: 25 Females who do not smoke: 50 This table is NOT a frequency distribution because the classes are not what?

exhaustive

A student was studying the political party preferences of a university's student population. The survey instrument asked students to identify themselves as a Democrat or a Republican. This question is flawed because the categories are not what?

mutually exclusive

For a frequency distribution of qualitative data, if the observations can be assigned to only one class, the classes are ______?

geometric mean

The _____ is the nth root of n observations.

descriptive statistics

The branch of statistics in which data is collected, analyzed and presented in a concise format is called ________?

length

The coefficient of variation for a set of annual incomes is 18%; the coefficient of variation for the length of service with the company is 29%. This indicates that there is more dispersion in the ______ of service compared with incomes

ratio

The incomes of a group of 50 loan applicants are obtained. Which level of measurement is income?

middle 50%

The interquartile range describes the ______ of the observations

summarize

The main purpose of descriptive statistics is to _______ data in a useful and informative manner.

class mark

The midpoint of a class interval is also called a _____?

box plot

The minimum, maximum, median, first and third quartiles are statistics needed to draw a what?

mode

The value that occurs most often in a set of data is called the _____?

negatively skewed

The weekly sales from a sample of ten computer stores yielded a mean of $25,900; a median $25,000 and a mode of $24,500. What is the shape of the distribution?

predicting

The word _____ is NOT part of the definition of descriptive statistics.

frequency distribution

This table is an example of what?

9

Three persons earn $8 an hour (3x8=24), and one earns $12 an hour (1x12=12). What is the weighted mean hourly wage?

sum

To convert a frequency distribution to a relative frequency distribution, divide each class frequency by the ____ of the class frequencies

pie chart

What chart or graph is useful for illustrating relative frequencies of a nominal variable?

ordinal

What is the lowest level of measurement that a median can be computed?

29.5

What is the median of 26, 30, 24, 32, 32, 31, 27, and 29?

class frequency

What is the number of observations in each class of a frequency distribution called?

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

5

~refer to Chpt 4. problems chart~ What is the median for the distribution of number of sales per hour?

5 (median)

~refer to Chpt. 4 problems chart~ For the distribution of number of sales per hour, 50% are greater than ___?

4 (first quartile), 6.5 (third quartile)

~refer to Chpt. 4 problems chart~ For the distribution of number of sales per hour, 50% of the observations are between ____ and ____

4

~refer to Chpt. 4 problems chart~ What is the first quartile for the distribution of number of sales per hour?

6.5

~refer to Chpt. 4 problems chart~ What is the third quartile for the distribution of number of sales per hour?