QNT 275 Week 5 Final Exam

Chapter 01, Testbank, Question 012

Your answer is correct.

A quantitative variable is the only type of variable that can:

have no intermediate values

assume numeric values for which arithmetic operations make sense

be graphed

be used to prepare tables

Chapter 01, Testbank, Question 015

Your answer is correct.

A qualitative variable is the only type of variable that:

can assume numerical values

cannot be graphed

can assume an uncountable set of values

cannot be measured numerically

Chapter 02, Testbank, Question 067-072

Correct.

The following table gives the cumulative frequency distribution of the commuting time (in minutes) from home to work for a sample of 400 persons selected from a city.

Time (minutes)   f

0 to less than 10  66

0 to less than 20  148

0 to less than 30  220

0 to less than 40  294

0 to less than 50  356

0 to less than 60  400

The sample size is:

The percentage of persons who commute for less than 30 minutes, rounded to two decimal places, is:

%

The cumulative relative frequency of the fourth class, rounded to four decimal places, is:

The percentage of persons who commute for 40 or more minutes, rounded to two decimal places, is:

%

The percentage of persons who commute for less than 50 minutes, rounded to two decimal places, is:

%

The number of persons who commute for 20 or more minutes is:

Chapter 03, Testbank, Question 027-029

The temperatures (in degrees Fahrenheit) observed during seven days of summer in Los Angeles are:

78,99,68,91,97,75,85

The range of these temperatures is:

The variance of these temperatures, rounded to three decimals, is:

The standard deviation, rounded to three decimals, of these temperatures is:

Chapter 04, Testbank, Question 021-026

Your answer is  correct.

The following table gives the two-way classification of 500 students based on sex and whether or not they suffer from math anxiety.

Suffer From Math Anxiety

Sex  Yes  No

Male      151 89

Female  184 76

If you randomly select one student from these 500 students, the probability that this selected student is a female is:   (round your answer to three decimal places, so 0.0857 would be 0.086)

If you randomly select one student from these 500 students, the probability that this selected student suffers from math anxiety is:   (round your answer to three decimal places, so 0.0857 would be 0.086)

If you randomly select one student from these 500 students, the probability that this selected student suffers from math anxiety, given that he is a male is:   (round your answer to three decimal places, so 0.0857 would be 0.086)

If you randomly select one student from these 500 students, the probability that this selected student is a female, given that she does not suffer from math anxiety is:   (round your answer to three decimal places, so 0.0857 would be 0.086)

Which of the following pairs of events are mutually exclusive?

Male and no

No and yes

Male and yes

Female and yes

Female and male

Female and no

Are the events “Has math anxiety” and “Person is female” independent or dependent? Detail the calculations you performed to determine this.

Chapter 05, Testbank, Question 009

Your answer is correct.

For the probability distribution of a discrete random variable x, the sum of the probabilities of all values of x must be:

equal to 1

equal to zero

in the range zero to 1

equal to 0.5

Chapter 05, Testbank, Question 034-035

Your answer is correct.

The following table lists the probability distribution of a discrete random variable x:

x     2     3     4     5     6     7     8

P(x) 0.15       0.3  0.24       0.13       0.1  0.06       0.02

The mean of the random variable x is:

The standard deviation of the random variable x, rounded to three decimal places, is:

Chapter 06, Testbank, Question 036-038

The daily sales at a convenience store produce a distribution that is approximately normal with a mean of 1270 and a standard deviation of 136.

The probability that the sales on a given day at this store are more than

1,405, rounded to four decimal places, is:

The probability that the sales on a given day at this store are less than

1,305, rounded to four decimal places, is:

The probability that the sales on a given day at this store are between

1,200 and 1,300, rounded to four decimal places, is:

Chapter 08, Testbank, Question 010

Your answer is correct.

The width of a confidence interval depends on the size of the:

population mean

margin of error

sample mean

none of these

Chapter 08, Testbank, Question 014

Your answer is correct.

A sample of size 67 from a population having standard deviation

= 41 produced a mean of 248.00. The 95% confidence interval for the population mean (rounded to two decimal places) is:

The lower limit is

The upper limit is

Chapter 09, Testbank, Question 001

The null hypothesis is a claim about a:

population parameter, where the claim is assumed to be true until it is declared false

population parameter, where the claim is assumed to be false until it is declared true

statistic, where the claim is assumed to be false until it is declared true

statistic, where the claim is assumed to be true until it is declared false

Chapter 09, Testbank, Question 002

Your answer is correct.

The alternative hypothesis is a claim about a:

statistic, where the claim is assumed to be true if the null hypothesis is declared false

population parameter, where the claim is assumed to be true if the null hypothesis is declared false

statistic, where the claim is assumed to be false until it is declared true

population parameter, where the claim is assumed to be true until it is declared false

Chapter 09, Testbank, Question 003

Your answer is correct.

In a one-tailed hypothesis test, a critical point is a point that divides the area under the sampling distribution of a:

statistic into one rejection region and one nonrejection region

population parameter into one rejection region and one nonrejection region

statistic into one rejection region and two nonrejection regions

population parameter into two rejection regions and one nonrejection region

Chapter 09, Testbank, Question 004

Your answer is correct.

In a two-tailed hypothesis test, the two critical points are the points that divide the area under the sampling distribution of a:

statistic into two rejection regions and one nonrejection region

statistic into one rejection region and two nonrejection regions

population parameter into two rejection regions and one nonrejection region

population parameter into one rejection region and one nonrejection region

Chapter 09, Testbank, Question 005

Your answer is correct.

In a hypothesis test, a Type I error occurs when:

a true null hypothesis is rejected

a false null hypothesis is rejected

a false null hypothesis is not rejected

a true null hypothesis is not rejected

Chapter 09, Testbank, Question 006

Correct answer.   Your answer is correct.

In a hypothesis test, a Type II error occurs when:

Entry field with correct answer

a false null hypothesis is not rejected

a true null hypothesis is rejected

a true null hypothesis is not rejected

a false null hypothesis is rejected

Chapter 09, Testbank, Question 007

Correct answer.   Your answer is correct.

In a hypothesis test, the probability of committing a Type I error is called the:

Entry field with correct answer

confidence interval

significance level

beta error

confidence level