Question

Answer the following problems.

1. Find the values of t for which the area on the right tail of the t-distribution is 0.05 and the number of degrees of freedom is equal to:

a. 15 b. 28 c. 100

2. Find the 99th percentile of the t-distribution with 18 degrees of freedom.

3. Find the 90th percentile of the t-distribution if the sample size is 25.

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Answer 1

1.

a. $t=1.75305$

b. $t=1.701131$

c. $t=1.660234$

2.

99th percentile $(\alpha=0.01)$

$t=2.55238$

3.

90th percentile $(\alpha=0.10), df=n-1=25-1=24$

$t=1.317836$