×
×

# Find the value of tn-1,?/2 needed to construct a two-sided

ISBN: 9780073401331 38

## Solution for problem 1E Chapter 5.3

Statistics for Engineers and Scientists | 4th Edition

• Textbook Solutions
• 2901 Step-by-step solutions solved by professors and subject experts
• Get 24/7 help from StudySoup virtual teaching assistants

Statistics for Engineers and Scientists | 4th Edition

4 5 1 409 Reviews
24
2
Problem 1E

Problem 1E

Find the value of tn-1,α/2 needed to construct a two-sided confidence interval of the given level with the given sample size:

a. Level 90%, sample size 12.

b.Level 95%, sample size 7.

c.Level 99%, sample size 2.

d.Level 95%, sample size 29.

Step-by-Step Solution:

Step 1 of 5:

We need to find the value of needed to construct a two-sided confidence interval of the given level with the given sample size.

Step 2 of 5:

a). Given that the confidence level is 90% and the sample size is n = 12.

Therefore,

% = 90% =

(1 - 0.9) = 0.1

Then,

The level of significance = 0.05.

And the degrees of freedom, DF = n - 1

= 12-1

= 11

Therefore, the critical value of ‘t’ is

( This value from statistical table, we have to see in 0.05 column and 11th row).

Step 3 of 5:

b). Given that the confidence level is 95% and the sample size is n = 7.

Therefore,

% = 95% =

(1 - 0.95) = 0.05

Then,

The level of significance = 0.025.

And the degrees of freedom, DF = n - 1

= 7-1

= 6

Therefore, the critical value of ‘t’ is

( This value from statistical table, we have to see in 0.025 column and 6th row).

Step 4 of 5

Step 5 of 5

#### Related chapters

Unlock Textbook Solution