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.