# Mathematics

The data presented in the table below resulted from an experiment in which seeds of 5 different types were planted and the number of seeds that germinated within 5 weeks after planting was recorded for each seed type. At the .01

level of significance, is the proportion of seeds that germinate dependent on the seed type?

Observed Frequencies

Germinated

Failed to Germinate

1

7

57

33

3

87

60

4

52

44

5

Seed Type

31

2

10

19

A.Yes, because the test value 16.86 is greater than the critical value of 13.28

B.Yes, because the test value 16.86 is less than the critical value of 14.86

C.No, because the test value 16.86 is greater than the critical value of 13.28

D.No, because the test value 13.28 is less than the critical value of 16.86

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Question 2 of 23

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The chi-square goodness-of-fit test can be used to test for:

A.normality

B.significance of sample statistics

C.difference between population variances

D.difference between population means

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Part 2 of 16 –

Question 3 of 23

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A single variable X can explain a large percentage of the variation in some other variable Y when the two variables are:

A.highly correlated

B.directly related

C.mutually exclusive

D.inversely related

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Question 4 of 23

The standard error of the estimate, sest, is essentially the

A.standard deviation of the explanatory variable

B.mean of the explanatory variable

C.mean of the residuals

D.standard deviation of the residuals

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Question 5 of 23

In regression analysis, the variable we are trying to explain or predict is called the

A.regression variable

B.dependent variable

C.residual variable

D.independent variable

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Part 3 of 16 –

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Question 6 of 23

Q-Mart is interested in comparing its male and female customers. Q-Mart would like to know if the amount of money

spent by its female charge customers differs, on average, from the amount spent by its male charge customers.

To answer this question, an analyst collected random samples of 25 female customers and 22 male customers. Based

on these samples, on average, the 25 women charge customers spent $102.23 and the 22 men charge customers

spent $86.46. Moreover, the sample standard deviation of the amount charged by the 25 women was $93.393, and the

sample standard deviation of the amount charged by the 22 men was $59.695.

Using the procedure advocated by Bluman, at the 10% level of significance, is there sufficient evidence for Q-Mart to

conclude that, on average, the amount spent by women charge customers differs from the amount spent by men

charge customers.

A.No, the p-value of this test is less than 0.10.

B.Yes, the test value does not exceed the critical value

C.No, the test value does not exceed the critical value.

D.Yes, the p-value of this test is greater than 0.10

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Question 7 of 23

Two independent samples of sizes n1 = 50 and n2 = 50 are randomly selected from two populations to test the

difference between the population means,

difference,

. The sampling distribution of the sample mean

is:

A.normally distributed

B.chi-squared distributed with 99 degrees of freedom

C.approximately normal

D.t – distributed with 98 degrees of freedom

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Part 4 of 16 –

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Question 8 of 23

You conduct a hypothesis test and you observe values for the sample mean and sample standard deviation when n =

25 that do not lead to the rejection of H0. You calculate a p-value of 0.0667. What will happen to the p-value if you

observe the same sample mean and standard deviation for a sample size larger than 25?

A.The p – value decreases

B.The p – value stays the same

C.The p – value increases

D.The p – value may increase or decrease

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Question 9 of 23

Results from previous studies showed 79% of all high school seniors from a certain city

plan to attend college after graduation. A random sample of 200 high school seniors from

this city reveals that 162 plan to attend college. Does this indicate that the percentage has

increased from that of previous studies? Test at the 5% level of significance.

Compute the z or t value of the sample test statistic.

A.t = 1.645

B.z = 0.69

C.z = 0.62

D.z = 1.96

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Question 10 of 23

In an article appearing in Today’s Health a writer states that the average number of calories in a serving of popcorn is

75. To determine if the average number of calories in a serving of popcorn is different from 75, a nutritionist selected a

random sample of 20 servings of popcorn and computed the sample mean number of calories per serving to be 78 with

a sample standard deviation of 7.

State the null and alternative hypotheses.

A.H0:

= 75, H1:

≠ 75

B.H0:

= 75, H1:

> 75

C.H0:

75, H1:

< 75

D.H0:

75, H1:

> 75

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Part 5 of 16 –

Question 11 of 23

1.0 Points

A previous study of nickels showed that the standard deviation of the weight of nickels is 150 milligrams. How many

nickels does a coin counter manufacturer need to weigh so that she can be 98% confident that her sample mean is

within 25 milligrams of the true average weight of a nickel?

A.36

B.196

C.239

D.139

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Question 12 of 23

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From a sample of 500 items, 30 were found to be defective. The point estimate of the population proportion defective

will be:

A..06

B.0.60

C.30

D.16.667

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Part 6 of 16 –

Question 13 of 23

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The mean of a probability distribution is a:

A.measure of relative likelihood

B.measure of variability of the distribution

C.measure of central location

D.measure of skewness of the distribution

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Part 7 of 16 –

Question 14 of 23

1.0 Points

If a gambler rolls two dice and gets a sum of 10, he wins $10, and if he gets a sum of

three, he wins $20. The cost to play the game is $5. What is the expectation of this

game?

A.$3.06

B.-$2.78

C.-$3.06

D.$2.78

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Part 8 of 16 –

Question 15 of 23

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A furniture manufacturer offers bookcases in 5 different sizes and 3 different colors. If every color is available in every

size, then the total number of different bookcases is

A.5

B.8

C.15

D.30

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Part 9 of 16 –

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Question 16 of 23

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as

thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be

used as the decimal point marker.

Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.

For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

Staples, a chain of large office supply stores, sells a line of desktop and laptop computers. Company

executives want to know whether the demands for these two types of computers are dependent on one

another. Each day’s demand for each type of computers is categorized as Low, Medium-Low, MediumHigh, or High. The data shown in the table below is based on 200 days of operation. Based on these data,

can Staples conclude that demands for these two types of computers are independent? Test at the 5% level

of significance.

desktops

low

med-high

high

low

3

14

14

4

35

med-low

6

18

17

22

63

med-high

13

16

11

16

56

high

8

14

15

9

46

30

laptops

med-low

62

57

51

200

What is the test value for this hypothesis test?

Answer:

Round your answer to two decimal places.

What is the critical value for this hypothesis test?

Answer:

Round your answer to two decimal places.

What is the conclusion for this hypothesis test? Choose one.

1. At the .05 level of significance, Staples can conclude that demands for these two types of computers are

independent.

2. At the .05 level of significance, Staples can conclude that demands for these two types of computers are

dependent.

Answer:

Enter only a 1 or 2 for your answer.

Part 10 of 16 –

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