Reference no: EM13245112
The city of Oakdale wishes to see if there is a linear relationship between the temperature and the amount of electricity used (in kilowatts). Based on the data in the table below, is there a significant linear relationship between temperature and the amount of electricity used? These data are also available in the worksheet temperature in the Excel workbook Temperature.xlsx.
Temperature.xlsx
Temperature (x)
73
78
85
98
93
81
76
105
Kilowatts (y)
680
760
910
1510
1170
837
600
1800
A.No, the sample correlation coefficient is equal to 0.981, which does not provide evidence of a significant linear relationship.
B.Yes, the sample correlation coefficient is equal to 0.981, which provides evidence of a significant linear relationship.
C.No, the sample correlation coefficient is equal to 0.098, which does not provide evidence of a significant linear relationship.
D.Yes, the sample correlation coefficient is equal to 0.878, which provides evidence of a significant linear relationship. Reset Selection
Part 3 of 16 -
Question 6 of 23
1.0 Points
An investor wants to compare the risks associated with two different stocks. One way to measure the risk of a given stock is to measure the variation in the stock's daily price changes.
In an effort to test the claim that the variance in the daily stock price changes for stock 1 is different from the variance in the daily stock price changes for stock 2, the investor obtains a random sample of 21 daily price changes for stock 1 and 21 daily price changes for stock 2.
The summary statistics associated with these samples are: n1 = 21, s1 = .725, n2 = 21, s2 = .529.
If you compute the test value by placing the larger variance in the numerator, at the .05 level of significance, would you conclude that the risks associated with these two stocks are different?
A.No, the p-value associated with this test is 0.0528
B.Yes, the p-value associated with this test is 0.0264
C.No, the test value of 1.371 does not exceed the critical value of 2.12
D.No, the test value of 1.879 does not exceed the critical value of 2.46 Reset Selection
Multiple myeloma or blood plasma cancer is characterized by increased blood vessel formulation in the bone marrow that is a prognostic factor in survival. One treatment approach used for multiple myeloma is stem cell transplantation with the patient's own stem cells. The following data represent the bone marrow microvessel density for a sample of 7 patients who had a complete response to a stem cell transplant as measured by blood and urine tests. Two measurements were taken: the first immediately prior to the stem cell transplant, and the second at the time of the complete response.
Patient
1
2
3
4
5
6
7
Before
158
189
202
353
416
426
441
After
284
214
101
227
290
176
290
Suppose you wanted to conduct a test of hypothesis to determine if there is sufficient evidence to conclude that the mean bone marrow microvessel density is higher before the stem cell transplant than after the stem cell transplant? What is the p-value associated with the test of hypothesis you would conduct?
A.p = .942597
B.p = .114986
C.p = .885014
D.p = .057493 Reset Selection
A type II error occurs when:
A.the sample mean differs from the population mean
B.the test is biased
C.the null hypothesis is incorrectly accepted when it is false
D.the null hypothesis is incorrectly rejected when it is true Reset Selection
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.
Compute the z or t value of the sample test statistic.
A.z = 1.645
B.t = -1.916
C.t = 1.916
D.z = 1.916 Reset Selection
The "Pizza Hot" manager commits a Type I error if he/she is
A.staying with old style when new style is no better than old style
B.switching to new style when it is no better than old style
C.switching to new style when it is better than old style
D.staying with old style when new style is better Reset Selection
If you increase the confidence level, the confidence interval ____________.
A.stays the same
B.increases
C.decreases
D.may increase or decrease, depending on the sample data Reset Selection
Find the 95% confidence interval for the standard deviation of the lengths of pipes if a sample of 26 pipes has a standard deviation of 10 inches.
A.14.0 < f$sigma f$ < 16.0
B.7.8 < f$sigma f$ < 13.8
C.74.0 < f$sigma f$ < 126.0
D.60.8 < f$sigma f$ < 190.5 Reset Selection
The standard deviation of a probability distribution is a:
A.measure of variability of the distribution
B.measure of relative likelihood
C.measure of skewness of the distribution
D.measure of central location
Reset Selection
The following data were obtained from a survey of college students. The variable X represents the number of non-assigned books read during the past six months.
x
0
1
2
3
4
5
P (X=x)
0.20
0.25
0.20
0.15
0.10
0.10
Find P(1 < X < 5)
A.0.45
B.0.30
C.0.70
D.0.20 Reset Selection
In a recent study, the following data were obtained in response to the question, "Do you favor recycling in your neighborhood?"
Yes
No
No Opinion
Males
25
15
10
Females
30
10
10
If a person is picked at random, what is the probability that the person is either male or has no opinion regarding recycling?
A.3/5
B.3/10
C.4/5
D.7/10 Reset Selection
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, Medium-High, 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-low med-high high
low 3 14 14 4 35
laptops med-low 6 18 17 22 63
med-high 13 16 11 16 56
high 8 14 15 9 46
30 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.
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.
A company has observed that there is a linear relationship between indirect labor expense (ILE) , in dollars, and direct labor hours (DLH). Data for direct labor hours and indirect labor expense for 18 months are given in the file ILE_and_DLH.xlsx
Treating ILE as the response variable, use regression to fit a straight line to all 18 data points.
Using your estimated regression output, predict the indirect labor expenses for a month in which the company has 31 direct labor hours.
Place your answer, rounded to 1 decimal place, in the blank. Do not use any stray punctuation marks or a dollar sign. For example, 458.9 would be a legitimate entry.
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.
Are America's top chief executive officers (CEOs) really worth all that money? One way to answer this question is to look at the annual company percentage increase in revenue versus the CEO's annual percentage salary increase in that same company. Suppose that a random sample of companies yielded the following data:
percent change for corporation 15 12 3 12 28 6 8 2
percent change for CEO 6 17 -4 12 32 -1 7 2
Do these data indicate that the population mean percentage increase in corporate revenue is greater than the population mean percentage increase in CEO salary? Use a 5% level of significance. What is the critical value that you would use to conduct this test of hypothesis? Place your answer, rounded to 3 decimal places, in the blank. For example, 2.345 would be a legitimate entry.
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.
A Wendy's fast-food restaurant sells hamburgers and chicken sandwiches. On a typical weekday, the demand for hamburgers is normally distributed with a mean of 450 and standard deviation of 80 and the demand for chicken sandwiches is normally distributed with a mean of 120 and standard deviation of 30.
How many chicken sandwiches must the restaurant stock to be 99% sure of not running out on a given day? Place you answer, rounded to the nearest whole number in the blank. For example, 345 would be a legitimate entry.
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.
You are told that a random sample of 150 people from Iowa has been given cholesterol tests, and 60 of these people had levels over the "safe" count of 200. Construct a 95% confidence interval for the population proportion of people in Iowa with cholesterol levels over 200. Place your LOWER limit, rounded to 3 decimal places, in the first blank . For example, .678 would be a legitimate entry. Place your UPPER limit, rounded to 3 decimal places, in the second blank . For example, .789 would be a legitimate entry.
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.
Suppose that the probability that a new medication will cause a bad side effect is 0.03. If this medication is given to 150 people, what is the probability that more than three of them will experience a bad side effect? Place your answer, rounded to 4 decimal places, in the blank. For example, 0.1776 would be a legitimate answer.
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.
Suppose a firm that produces light bulbs wants to know whether it can say that its light bulbs typically last more than 1500 hours. Hoping to find support for their claim, the firm collects a random sample of n = 25 light bulbs and records the lifetime (in hours) of each bulb. The information related to the hypothesis test is presented below.
Test of H0: f$mu leq f$ 1500 versus H1:f$mu f$ > 1500
Sample mean 1509.5
Std error of mean 4.854
What is the test value that you would use to conduct this test? Place your answer, rounded to 3 decimal places in the blank. For example, 1.234 would be a legitimate entry.
Part 16 of 16 -
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.
Mothers Against Drunk Driving (MADD) is a very visible group whose main focus is to educate the public about the harm caused by drunk drivers. A study was recently done that emphasized the problem we all face with drinking and driving. Five hundred accidents that occurred on a Saturday night were analyzed. Two items noted were the number of vehicles involved and whether alcohol played a role in the accident. The numbers are shown below:
Number of Vehicles Involved Did alcohol play a role?
1
2
3
Yes
60
110
30
200
No
40
215
45
300
100
325
75
Given that alcohol was not involved, what proportion of the accidents were multiple vehicle? Place your answer, rounded to 2 decimal places, in the blank. For example, 0.23 is a legitimate entry.