Question

A clinical psychologist wished to compare three methods for reducing hostility levels in university students using a certain psychological test (HLT). High scores on this test were taken to indicate great hostility, and 11 students who got high and nearly equal scores were used in the experiment. Five were selected at random from among the 11 students and treated by method A, three were taken at random from the remaining six students and treated by method B, and the other three students were treated by method C. All treatments continued throughout a semester, when the HLT test was given again. The results are shown in the table.

Method |
Scores on the HLT Test |
||||

A | 72 | 84 | 77 | 67 | 79 |

B | 55 | 75 | 72 | ||

C | 79 | 96 | 88 |

Let *μ*_{A} and *μ*_{B},
respectively, denote the mean scores at the end of the semester for
the populations of extremely hostile students who were treated
throughout that semester by method A and method B.

(a) Find a 95% confidence interval for *μ*_{A}.
(Round your answers to two decimal places.)

_ to _

(b) Find a 95% confidence interval for *μ*_{B}.
(Round your answers to two decimal places.)

_ to _

(c) Find a 95% confidence interval for (*μ*_{A} −
*μ*_{B}). (Round your answers to two decimal
places.)

_ to _

this is all of the information I was provided.

Answer #1

A clinical psychologist wished to compare three methods for
reducing hostility levels in university students using a certain
psychological test (HLT). High scores on this test were taken to
indicate great hostility, and 11 students who got high and nearly
equal scores were used in the experiment. Five were selected at
random from among the 11 students and treated by method A, three
were taken at random from the remaining six students and treated by
method B, and the other...

A psychologist wants to compare three methods for reducing
hostility levels in university students. Eleven students were
judged to have "great hostility," based on a certain psychological
test (HLT). These students were then randomly divided into three
groups—five were treated by Method A, three were treated by Method
B, and the other three students were treated by Method C. All
treatments continued throughout a semester, at the end of which the
HLT test was given again. The results are shown...

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Step 1 of...

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74,79,83,85,88,90,94,95,95,97,99,99,100,103,105,105,106,107,107,108
Calculate the sample mean (?⎯⎯⎯x¯), sample standard deviation
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The test-retest method is one way of establishing the
reliability of a test. The test is administered, and then, at a
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two sets of scores. The following test scores were obtained in a
test-retest situation. (Round your answers to two decimal
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75
87
60
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98
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68
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47
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Each of the students was asked whether or not they were employed
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Step 1 of...

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Each of the students was asked whether or not they were employed
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Step 1 of...

An education minister would like to know whether students at
Gedrassi high school on average perform better at English or at
Mathematics. Denoting by μ1 the mean score for all
Gedrassi students in a standardized English exam and μ2
the mean score for all Gedrassi students in a standardized
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A study was conducted where many students were given...

Question #1
For this problem, carry at least four digits after the decimal
in your calculations. Answers may vary slightly due to
rounding.
Santa Fe black-on-white is a type of pottery commonly found at
archaeological excavations at a certain monument. At one excavation
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