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The average running time for Broadway shows is 2 hours and 12 minutes. A producer in another city claims that the length of time of productions in his city is the same. He samples 8 shows and finds the time to be 2 hours and 5 minutes with a standard deviation of 11 minutes. Using , is the producer correct?
The SRTC gets its budget for a training program on the assumption that the average of the supplies is to be P12, 000 or less. To see if this claim is realistic, 10 supply figures are randomly obtained from similar training programs. The sample has yielded a mean =P12, 900 and s = P1, 100. Is the mean greater than P12, 000? Use to test the hypothesis.
Suppose a statistician chose to test a hypothesis at . the critical value for a right-tailed test is . If the test value was , what would the decision be? What would happen if, after seeing the test value, she decided to choose ? What would the decision be? Explain the contradiction, if there is one.
Experts claim that 10% of murders are committed by women. Is there enough evidence to reject the claim if in a sample of 67 murders, 10 were committed by women? At , test the hypothesis using the p-value method
a. 37 Ã ¢ 49
b. 88 Ã ¢ 105
c. 875 Ã ¢ 899
d. 12.3 Ã ¢ 15.5
e. 3.17 Ã ¢ 5. 89
Use the traditional method in testing the hypothesis.
a. State the hypotheses and identify the claim.
b. Find the critical value(s)
c. Find the test value
d. Make the decision
e. Summarize the result
Based on previous research and sound theoretical considerations, a cognitive psychologist believes that memory for pictures are superior to memory for words. To test this hypothesis, the psychologist performs an experiment in which students from an introductory psychology class are used as subjects. Eight randomly selected students view 30 slides with nouns printed on them, and another group of eight randomly selected students’ views 30 slides with pictures of the same nouns. Each slide contains either one noun or one picture and is viewed for 4 seconds. After viewing the slides, subjects are given a recall test, and the number of correctly remembered items is measured. The data follow: Use ∝= 0.05.
No. of Pictures Recalled: 18 21 14 25 23 19 26 15
No. of Nouns Recalled: 12 9 21 17 16 10 19 22
1. Explain the difference between testing a single mean and testing the difference between two means.
2. What two assumptions must be met when you are using the z test to test differences between two means? Can the sample standard deviations 𝑠1 and 𝑠2 be used in place of the population standard deviations 𝜎1 and 𝜎2?
In each problem, provide the following:
a. State the hypotheses and identify the claim.
b. Find the critical value(s)
c. Find the test value
d. Make the decision
e. Summarize the result
2. An industrial psychologist obtains scores on a job-selection test from 41 men and 31
women, with the following results: men, M = 48.75 (SD = 9.0); women, M = 46.07 (SD
= 10.0). Test this difference for significance at both the .05 and .01 levels (two-tailed).
(Use 𝑷-value method)
In each problem, provide the following:
a. State the hypotheses and identify the claim.
b. Find the critical value(s)
c. Find the test value
d. Make the decision
e. Summarize the result
1. A researcher claims that students in a private school have exam scores that are at most 8 points higher than those of students in public schools. Random samples of 60 students from each type of school are selected and given an exam. The results are shown. At ∝= 0.05, test the claim. (Use traditional method)
_
Private 𝑿𝟏 = 𝟏𝟏𝟎 𝝈𝟏 = 𝟏𝟓 𝒏𝟏 = 𝟔0
_
Public 𝑿𝟐 = 𝟏𝟎𝟐 𝝈𝟐 = 𝟏𝟓 𝒏𝟐 = 𝟔0
A budget head for SSS Sales Inc. would like to compare the daily travel expenses for the sales staff and the audit staff. He collected the following sample information.
Sales Staff
105
120
140
160
100
170
160
140
130
160
180
190
Audit Staff
130
50
90
80
70
125
180
80
110
At 0.05 significance level, can he conclude that the mean daily expenses of sales staff are greater than the audit staff?
#332078 on Oct 2022