gupta 1-8 quiz

The number of weekly sales callls by a sample of 25 pharmaceutical salesperson is below. 24,56,43,35,37,27,29,44,34,28,33,28,46,31,38,41,48,38,27,29,37,33,31,40,50 How many classes should be used in construction of a histogram?

5

Using the following probability distribution table of the random variable x, what is the probability of x=3?

5/15

What is the probability of rolling a seven with a pair of fair dice?

6/36

In a statistics class, the following 10 scores were randomly selected: 74,73,77,71,68,65,77,67,66. What is the mean?

71.5

In a statistics class, the following 10 scores were randomly selected: 74,73,77,71,68,65,77,67,66. What is the median?

72.0

In a statistics class, the following 10 scores were randomly selected: 74,73,77,71,68,65,77,67,66. What is the mode?

77.0

A random variable

Assigns one an only one numeric value to each experimental outcome.

a ____ displays the frequency oof each class with qualitative data and a _____ displays the frequency of each class with quantitative data.

Bar chart, histogram

A discrete probability distribution is expressed as a table, graph, or _______ that gives the probability associated with each possible value that the random variable can assume.

Formula

The area under the normal curve between z=0 and z=1 is _______ the area under the normal curve between z=1 and z=2

Greater than

which of the following divides quantitative measurements into classes and graphs the frequency, relative frequency, or percentage frequency for each class?

Histogram

As the sample size ________, the variation of the sampling distribution of x _____ decreases, decreases

Increases, decreases

For nonnormal populations, as the sample size(N) ________, the distribution of the sample means approaches a ______ distribution.

Increases, normal

The central limit theorem states that as the sample increases, the distribution of the sample _________ approaches the normal distribution.

Means

The population of all sample proportions has a normal distribution if the sample size (N) is sufficiently large. The rule of thumb for ensuring that n is sufficiently large is

NP>5 and n(1-p)>5

Which of the following is not a discrete random variable?

The number of minutes required to run 1 mile

Which of the following is a continuous distribution?

Uniform

A standard normal distribution has a mean of _____ and standard deviation of ______

Zero, One

The following is a partial relative frequency distribution of grades in an introductory statistics course. Find the relative frequency for the B grade.

0.37

At a college, 70 percent of the students are women and 50 percent of the students receive a grade of C 25 percent of the students are neither female nor C students. Use this contingency table. What is the probability that a student is female and a C student?

0.45

what is the probability that an even number appears on the toss of a die?

0.5

Four people will enter an automobile showroom, and each will either purchase a car (P) or not purchase a car(N) (assume that all sample space outcomes are equally likely) What is the probability that exactly three people will purchase a car?

1/4

Four people will enter an automobile showroom, and each will either purchase a car (P) or not purchase a car(N) (assume that all sample space outcomes are equally likely) What is the probability that two or fewer people will purchase a car?

11/16

The following is a relative frequency distribution of grades in an introductory statistics course. If we wish to depict these data using a pie chart, find how many degrees (out of 360 degrees) should be assigned to grade B

133.2

Four people will enter an automobile showroom, and each will either purchase a car (P) or not purchase a car(N) (assume that all sample space outcomes are equally likely) What is the probability that one or more people will purchase a car.

15/16

Four people will enter an automobile showroom, and each will either purchase a car (P) or not purchase a car(N) How many sample space of all possible decisions that could be potentially made by the people.

16

Four people will enter an automobile showroom, and each will either purchase a car (P) or not purchase a car(N). (assume that all sample space outcomes are equally likely). What is the probability that all four people will make the same purchase decision?

2/16

which percentile describes the first quartile, Q1?

25th

A normal population has 99.73 percent of the population measurements within ___ standard deviation(s) of the mean

3

The following is a relative frequency distribution of grades in an introductory statistics course. If this was the distribution of 200 students, give the frequency distribution for grade A.

44

If the sampled population has a mean of 48 and a standard deviation of 26, then respectively, the mean and the standard deviation for the sampling distribution of x for n=16 are

48 and 4

The requirement that the probability of success remains constant from trial to trial is a property of the _____ distribution.

Binomial

a Quantity that measures the variation of a population or a sample relative to its mean is called the _______

Coefficient of variation

The ____ of event x consists of all sample space outcomes that do not correspond to occurrence of event X.

Complement

Which of the following is a measure of the strength of the linear relationship between x and y that is dependent on the units in which x and y are measured?

Covariance

All of the following are measures of central tendency except, the ____

Range

It is appropriate to use the uniform distribution to describe a continuous random variable x when

Relative frequencies of all possible values of x are about the same.

The _______ is the positive square root of the sample variance.

Sample standard deviation

which of the following graphical tools is not used to study the shapes of distributions?

Scatter plot

The number of weekly sales callls by a sample of 25 pharmaceutical salesperson is below. 24,56,43,35,37,27,29,44,34,28,33,28,46,31,38,41,48,38,27,29,37,33,31,40,50 What is the shape of the distribution of the data?

Skewed to the right

Values of the standard normal random variable are measured

in the number of standard deviation from the mean

If a population distribution is skewed to the right, then, given a random sample from that population, one would expect that the ________.

median would be less than the mean