BUSI STATS

The standard deviation of is referred to as the _____.

standard error of the mean

A sample of 26 elements from a normally distributed population is selected. The sample mean is 10 with a standard deviation of 4. The 90% confidence interval for μ is _____.

8.660 to 11.340

The probability distribution for the daily sales at Michael's Co. is given below. Daily Sales Probability 40 .1 50 .4 60 .3 70 .2 ​ Refer to Exhibit 5-2. The variance of the daily sales are _____.

84

The empirical rule states that, for data having a bell-shaped distribution, the portion of data values being within two standard deviation of the mean is approximately _____. 50% 68% 95% Almost all

95%

When using Excel to calculate a p-value for a lower-tail hypothesis test, which of the following must be used while using the Z-test ?

NORM.S.DIST

Excel's _____ function can be used to compute the third quartile QUARTILE.EXC(array, 0.25) QUARTILE.EXC(array, 0.50) QUARTILE.EXC(array, 0.75) None of the above

None of the above

Excel's _____ function can be used to compute the second quartile. PERCENTILE.EXC(array, 0.10) PERCENTILE.EXC(array, 0.25) PERCENTILE.EXC(array, 0.50) PERCENTILE.EXC(array, 0.75)

PERCENTILE.EXC(array, 0.50)

excel's _____ function can be used to compute the third quartile. PERCENTILE.EXC(array, 0.10) PERCENTILE.EXC(array, 0.25) PERCENTILE.EXC(array, 0.50) PERCENTILE.EXC(array, 0.75)

PERCENTILE.EXC(array, 0.75)

A random variable that can assume only a finite number of values is referred to as a(n) _____.

discrete random variable

The measure of location often used in analyzing growth rates in financial data is the _____. a. hyperbolic mean b. weighted mean c. geometric mean d. arithmetic mean

geometric mean

The measure of location often used in analyzing growth rates in financial data is the _____. a. weighted mean b. arithmetic mean c. geometric mean d. hyperbolic mean

geometric mean

Which of the following is a measure of dispersion? a. percentiles b. quartiles c. interquartile range d. All of the answers are correct.

interquartile range

The descriptive measure of dispersion that is based on the concept of a deviation about the mean is _____. a. the interquartile range b. both the range and the interquartile range c. the range d. neither the range nor the interquartile range

neither the range nor the interquartile range

As a general rule, the sampling distribution of the sample proportions can be approximated by a normal probability distribution whenever _____.

np ≥ 5 and n(1 − p) ≥ 5

A numerical measure, such as a mean, computed from a population is known as a _____. a. population statistic b. population parameter c. sample parameter d. sample statistic

population parameter

Read the z statistic from the normal distribution table and circle the correct answer. A two-tailed test at a 0.02 level of significance; z = _____.

-2.33 and 2.33

A population has a mean of 53 and a standard deviation of 21. A sample of 49 observations will be taken. The probability that the sample mean will be greater than 57.95 is _____.

.0495

In a binomial experiment, the probability of success is .06. What is the probability of two successes in seven trials?

.0554

Suppose x is a normally distributed random variable with a mean of 8 and a standard deviation of 4. The probability that x is between 1.48 and 15.56 is _____.

.9190

For any continuous random variable, the probability that the random variable takes on exactly a specific value is _____.

0

for a standard normal distribution, P(z ≥ 2.57) is _____ (choose the closest as your answer).

0.0051

For a standard normal distribution, P(z ≤ -2.33) is _____ (choose the closest as your answer).

0.0099

Assume z is a standard normal random variable. Then P(-1.96 < Z < 1.96) equals ______ (choose the closest answer).

0.9500

A population has a mean of 53 and a standard deviation of 21. A sample of 49 observations will be taken. The probability that the sample mean will be less than 57.95 is _____.

0.9505

AMR is a computer-consulting firm. The number of new clients that it has obtained each month has ranged from 0 to 6. The number of new clients has the probability distribution that is shown below. Number of New Clients Probability 0 .05 1 .10 2 .15 3 .35 4 .20 5 .10 6 .05 ​ Refer to Exhibit 5-5. The variance of the new clients per month is _____.

2.0475

A researcher has collected the following sample data. 10 8 11 8 8 11 6 5 11 10 The "sample" standard deviation (s) is ____ (to the closest two decimal points) 1.66 2.15 2.23 2.44 2.60 2.88

2.15

A researcher has collected the following sample data. 5 11 10 8 11 10 7 12 9 12 The "sample" standard deviation (s) is ____ (to the closest two decimal points) 2.17 2.27 2.41 2.60 2.87 2.88

2.27

Exhibit 9-1 n = 36H0: μ ≤ 20 = 24.6Ha: μ > 20 σ = 12 Refer to Exhibit 9-1. The test statistic equals _____.

2.3

Random samples of size 81 are taken from a process (an infinite population) whose mean and standard deviation are 200 and 18, respectively. The distribution of the population is unknown. The mean and the standard error of the distribution of sample means are _____.

200 and 2

The Chebyshev's Theorem states that, the portion of data values being within two standard deviation of the mean is at least _____.(Choose the closest as your answer.) 75% 89% 94% Almost all

75%

In a five-number summary, which of the following is NOT used for data summarization? a. largest value b. median c. smallest value d. mean

Mean

In a five-number summary, which of the following is NOT used for data summarization? a. smallest value b. median c. mean d. largest value

Mean

The weight of an object, measured to the nearest gram, is an example of _____.

a discrete random variable

A numerical measure from a population, such as a population mean, is called _____.

a parameter

Highway patrol officers measure the speed of automobiles on a highway using radar equipment. The random variable in this experiment is speed, measured in miles per hour. This random variable is a _____.

continuous random variable

The sample variance _____. a. could be smaller, equal to, or larger than the true value of the population variance b. is always smaller than the true value of the population variance c. can never be zero d. is always larger than the true value of the population variance

could be smaller, equal to, or larger than the true value of the population variance

Since the mode is the most frequently occurring data value, it _____. a. can never be larger than the mean b. is always larger than the median c. is always larger than the mean d. None of the answers is correct.

d. None of the answers is correct.

In regression analysis, the variable that is being predicted is the _____.

dependent variable

A normal probability distribution _____.

is a continuous probability distribution

Larger values of r 2 imply that the observations are more closely grouped about the _____.

least squares line

The finite correction factor should be used in the computation of when n/ N is greater than _____.

0.05

the mean cost of domestic airfares in the United States rose to an all-time high of $385 per ticket (Bureau of Transportation Statistics website, November 2, 2012). Airfares were based on the total ticket value, which consisted of the price charged by the airlines plus any additional taxes and fees. Assume domestic airfares are normally distributed with a standard deviation of $110. What is the cost for the highest 10% of domestic airfares? (choose the closest as your answer).

$525.8

Given that z is a standard normal random variable, what is the value of z if the area to the left of z is .1112?

-1.22

Read the t statistic from the table of t distributions and circle the correct answer. A one-tailed test (lower tail), a sample size of 20 at a .10 level of significance; t = _____.

-1.328

Read the z statistic from the normal distribution table and circle the correct answer. A one-tailed test (lower tail) at a 0.05 level of significance; z = _____.

-1.645

Read the t statistic from the table of t distributions and circle the correct answer. A one-tailed test (lower tail), a sample size of 20 at a .05 level of significance; t = _____.

-1.729

Random samples of size 100 are taken from a process (an infinite population) whose population proportion is .2. The mean and standard deviation of the distribution of sample proportions are _____.

.2 and .04

For a T-distribution with 15 degrees of freedom, find the area or the probability, to the right of 1.341.

0.10

A population has a mean of 180 and a standard deviation of 24. A sample of 64 observations will be taken. The probability that the mean from that sample will be between 183 and 186 is _____.

0.1359

For a standard normal distribution, P(z ≤ 2.57) is _____ (choose the closest as your answer).

0.9949

For a standard normal distribution, P(z ≥ -2.57) is _____ (choose the closest as your answer).

0.9949

Which of the following Excel stats function can be used to find the right area of z* under the standard normal distribution P(Z > z*)?

1 - norm.s.dist(z*, true)

Read the z statistic from the normal distribution table and circle the correct answer. A one-tailed test (upper tail) at a 0.10 level of significance; z = _____.

1.28

Read the t statistic from the table of t distributions and circle the correct answer. A one-tailed test (upper tail), a sample size of 18 at a .10 level of significance; t = _____.

1.333

Assume z is a standard normal random variable. What is the value of z if the area between -z and z is 0.9011?

1.65

Read the t statistic from the table of t distributions and circle the correct answer. A one-tailed test (upper tail), a sample size of 35 at a .05 level of significance; t = _____.

1.691

Read the t statistic from the table of t distributions and circle the correct answer. A two-tailed test, a sample of 30 at a .10 level of significance; t = _____.

1.691

Given that z is a standard normal random variable, what is the value of z if the area to the right of z is 0.0250.

1.96

The z value for a 95% confidence interval estimation is _____.

1.96

A researcher has collected the following sample data. 5 11 10 8 11 10 7 12 9 12 The median is ____. 6 7.5 8 8.5 9 10

10

A researcher has collected the following sample data. 6 8 9 10 11 11 7 9 10 8 The 80th percentile is ____. 9.8 10.8 11 11.2 11.8 12

10.8

A researcher has collected the following sample data. 5 6 12 7 6 5 8 12 5 4 The 80th percentile is ____. 9.8 10.8 11 11.2 11.8 12

11.2

A random sample of 36 students at a community college showed an average age of 25 years. Assume the ages of all students at the college are normally distributed with a standard deviation of 1.8 years. The 98% confidence interval for the average age of all students at this college is _____.

24.301 to 25.699

A researcher has collected the following sample data. 5 6 12 7 6 5 8 12 5 4 The median is ____.

6

bank manager wishes to estimate the average waiting time for customers in line for tellers. A random sample of 50 times is measured and the average waiting time is 5.7 minutes. The sample standard deviation of waiting time is 2 minutes. Which Excel function would be used to construct a confidence interval estimate?

CONFIDENCE.T

Excel's _____ function can be used to compute the first quartile. PERCENTILE.EXC(array, 0.10) PERCENTILE.EXC(array, 0.25) PERCENTILE.EXC(array, 0.50) PERCENTILE.EXC(array, 0.75)

PERCENTILE.EXC(array, 0.25)

Excel's _____ function can be used to compute the variance of a discrete random variable.

SUMPRODUCT

In simple linear regression analysis, which of the following is NOT true?

The F test and the t test may or may not yield the same results.

Which of the following is NOT a characteristic of an experiment where the binomial probability distribution is applicable?

The trials are dependent.

in regression analysis, which of the following is NOT a required assumption about the error term ε?

The variance of the error term is equal to 1.

Excel's _____ function can be used to compute the population variance. a. VAR.S b. VAR.C c. VAR.P d. None of the answers is correct.

VAR.P

Which of the following statements about a discrete random variable and its probability distribution is true?

Values of f(x) must be greater than or equal to zero.

Excel's _____ function can be used to compute the middle value of an ordered data set. a. MEDIAN b. MODE c. AVERAGE d. MAX

a. MEDIAN

Which of the following symbols represents the size of a population? a. σ b. σ 2 c. N d. μ

c. N

Which of the following symbols represents the mean of a population? a. μ b. σ c. σ 2 d. xbar

a. μ

The sum of deviations of the individual data elements from their mean is _____. a. always less than zero b. always greater than zero c. always equal to zero d. sometimes greater than and sometimes less than zero, depending on the data elements

always equal to zero

_____ can be used to make statements about the proportion of data values that must be within a specified number of standard deviations of the mean, regardless of the shape of the distribution. a. A five-number summary b. Chebyshev's theorem c. The empirical rule d. A box plot

b. Chebyshev's theorem

In statistics, what does IQR mean? a. individual quartile relativity b. inter-quartile range c. inter-quantity relativity d. individual quantity range

b. inter-quartile range

The manager of a grocery store has taken a random sample of 100 customers. The average length of time it took the customers in the sample to check out was 3.1 minutes and the sample standard deviation is known to be 0.5 minute. We want to test to determine whether or not the mean waiting time of all customers is significantly more than 3 minutes. Refer to Exhibit 9-2. The p-value is _____.

between 0.01 and 0.025

n = 36H0: μ ≤ 20 = 24.6Ha: μ > 20 s = 12 Refer to Exhibit 9-1. The p-value is _____.

between 0.01 and 0.025

Which of the following is NOT a measure of location? a. mode b. mean c. variance d. median

c. variance

Which of the following symbols represents the size of a sample? a. σ 2 b. σ c. n d. N

c. n

A numerical measure, such as a mean, computed from a population is known as a _____. a. sample statistic b. sample parameter c. population parameter d. population statistic

c. population parameter

Which of the following symbols represents the standard deviation of a population? a. μ b. σ^2 c. σ d. xbar

c. σ

The mean of a sample is _____. a. computed by summing all the data values and dividing the sum by the number of items b. computed by summing the data values and dividing the sum by (n − 1) c. always equal to the mean of the population d. always smaller than the mean of the population

computed by summing all the data values and dividing the sum by the number of items

Excel's _____ function can be used to compute the data value occurring most frequently. a. MEDIAN b. MAX c. AVERAGE d. MODE.SNGL

d. MODE.SNGL

Which of the following is a valid discrete random variable? f(1)=0.1, f(2)=0.2, and f(3)=0.3 f(x)= 1/6, x=0, 1, 2, 3, 4, 5 f(1)=0.3, f(2)=0.4, and f(3)=0.5 None of the above

f(x)= 1/6, x=0, 1, 2, 3, 4, 5

Under a probability normal distribution X with a mean μ, and a s.d. σ, which of the following Excel stats function can be used to find the left area of x*, that is, P(X < x*)?

norm.dist(x*, μ, σ, true)

Under a probability normal distribution X with a mean μ, and a s.d. σ, which of the following Excel stats function can be used to find the x-value for a given right area, α=0.05? That is, to find the x such that P(X > x) = 0.05.

norm.inv(0.95, μ, σ)

Under the standard normal distribution, which of the following Excel stats function can be used to find the z-value for a given right area, α = 0.05? That is, to find the z such that P(Z > z) = 0.05.

norm.s.inv(0.95)

As the degrees of freedom increase, the t distribution approaches the _____ distribution.

normal

The standard deviation is the _____.

positive square root of the variance

A two-tailed test is performed at a 1% level of significance. The p-value is determined to be .09. The null hypothesis _____.

should not be rejected

A weighted average of the value of a random variable, where the probability function provides weights, is known as _____.

the expected value

In the hypothesis testing procedure, α is _____.

the level of significance

The symbol σ^2 is used to represent the _____. a. standard deviation of a sample b. variance of a sample c. variance of a population d. standard deviation of a population

variance of a population

A simple random sample of size n from a finite population of size N is to be selected. Each possible sample should have _____.

the same probability of being selected

In developing an interval estimate of the population mean, if the population standard deviation is unknown _____.

the sample standard deviation and t distribution can be used

The level of significance is symbolized by _____.

α

Which of the following symbols represents the variance of a population? a. σ b. μ c. xbar d. σ^2

σ^2