1. In order to determine whether or not a cram shcool course improves the scores on

some statistics exam. A sample of 6 students were given the exam before and after taking

the course. The result s are shown below.

Student |
1 |
2 |
3 |
4 |
5 |
6 |

Before the Course |
83 |
89 |
93 |
77 |
86 |
79 |

After the Course |
87 |
88 |
91 |
77 |
93 |
83 |

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(a) What is ** the
standardized test statistic**? (

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(b) Based on ** the
standardized test statistic at10% level of significance**,

what is the conclusion?

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2. The following data presents the number of computer units sold per day by a sample

of 6 salespersons before and after a bonus plan was implemented.

Salesperson |
1 |
2 |
3 |
4 |
5 |
6 |

Before |
3 |
7 |
6 |
8 |
7 |
9 |

After |
6 |
5 |
6 |
7 |
8 |
8 |

(a) What is ** the standardized test
statistic**?

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(b) Based on ** the
standardized test statistic at 5% level of significance**,

what is the conclusion?

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3. To determine the effectiveness of a new weight control diet, 10 randomly selected students

students observed the diet for 4 weeks with the results shown below.

Dieter |
A |
B |
C |
D |
E |
F |
G |
H |
I |
J |

Weight Before |
138 |
151 |
129 |
125 |
168 |
139 |
152 |
140 |
137 |
180 |

Weight After |
135 |
147 |
132 |
127 |
155 |
131 |
144 |
142 |
137 |
180 |

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(a) Find** the
standard deviation** of

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(b) Suppose ** the
95% confidence interval estimate** for the true amount

is ** [x,y]**.
What is

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(c) Based on ** the
95% confidence interval**, what
is the conclusion?

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(d) What is *the
standardized test statistic*? (*to
3 digits*)

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(e) Based on ** the
standardized test statistic**, what
is the conclusion?

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