statistics test

The daily closing values of the dow jones industrial average over a period of 30 days are best described as _ data ?

Time series

Statisticians often refer to the pivot tables that display counts as contingency tables or crosstabs

True

according to the empirical rule, about 95% of the observations lie within plus and minus 2.00 standard deviations

True

scatter plots are referred to as

X and Y Charts

a useful way of comparing the distribution of a numerical variable across categories of some categorical variable ?

a side by side plot or side by side pivot

A population consists of all the weights of all defensive tackles on a university's football team. They are Johnson, 204 pounds; Patrick, 215 pounds; Junior, 207 pounds; Kendron, 212 pounds; Nicko, 214 pounds; and Cochran, 208 pounds. What is the population standard deviation (in pounds)?

about 4

Tables used to display counts of a categorical variable are called

both of the options

what does a scatter plot illustrate

both of those choices

Gender and states of residence are examples of ____ data.

categorical

coding males as 1 and females as 0 in a data set illustrates the use of

dummy variables

For any distribution there are an equal number of values above and below the mean

false

because they represent such extreme values, outliers should be eliminated from statistical analyses

false

for any distribtion there are an equal number of values above and below the mean

false

If P(A) = P(B), then events A and B are said to be :

independent

a disadvantage of using an arithmetic mean to summarize a set of data is that

it can be biased

What is a disadvantage of the range as a measure of dspersion ?

it is based on only two observations

To examine relationships between two categorical variables we can use

none of these choices

The tool that provides useful information about data set by breaking it down into categories

pivot table

If the variance of the number of daily parking tickets issued is 100, the standard deviation is defined as the

square root of the variance of the number of daily parking tickets

what is the relationship among the mean, median and mode in a symmetirc distribution ?

they are all equal

the filter filed of a pivot table contains the data that you want summarized

true

variation describes the degree of dispersion in the data

true

if events A and B are mutually exclusive, then the probability of both events occurring simultaneously is equal to : 0.0 0.5 1.0 any value between 0.5 and 1.o

0.0

suppose that patrons of a restaurant were asked whether they preferred beer or whether they preferred wine. 60% said they prefered beer. 70% of the patrons were male. 80% of the males preferred beer.

0.4

the ages of the patients in the isolation ward of the hospital are 38, 26, 13, 41,, and 22. what is the population variance

106.8

A sample of small bottles and their contents has the following weights (in grams): 4, 2, 5, 4, 5, 2, and 6. What is the sample variance of bottle weight?

2.33

A sample of single persons receiving social security payments revealed these monthly benefits: $826, $699, $1,087, $880, $839, and $965. 1 2 3 3.5

3

Assume that the histogram of a data set is symmetric and bell shaped, with a mean of 75 and standarddeviation of 10. Then, approximately 95% of the data values were between

55 and 95

the average score for a classs of 30 students was 75. the 20 male students in the class averaged 70. the 10 female students in the class averaged : 70 90 75 85

85

What is a disadvantage of the range as a measure of dispersion?

It is based on only two observations.