Question

Determine the upper-tail critical value ta/2 in each of the following circumstances.

a. 1 - a=0.95, n = 17
b. 1 - a=0.99, n = 17
c. 1 - a=0.95, n = 36
d. 1 - a=0.95, n = 52
e. 1 - a=0.90, n = 9

Critical Values of t. For a particular number of degrees of freedom, entry represents the critical value of t corresponding to the cumulative probability 1 minus alpha and a specified upper-tail area alpha.

Answer 1

To determine the upper-tail critical value (tα/2) for each given circumstance, we need to use the t-distribution table or a statistical software. The critical value is dependent on the significance level (α) and the degrees of freedom (df), which is equal to n - 1 for a sample size of n.

Using the t-distribution table or software, we can find the critical values for the given circumstances:

a. For 1 - α = 0.95 and n = 17:

The degrees of freedom (df) = 17 - 1 = 16.

The upper-tail critical value (tα/2) is approximately 2.120.

b. For 1 - α = 0.99 and n = 17:

The degrees of freedom (df) = 17 - 1 = 16.

The upper-tail critical value (tα/2) is approximately 2.583.

c. For 1 - α = 0.95 and n = 36:

The degrees of freedom (df) = 36 - 1 = 35.

The upper-tail critical value (tα/2) is approximately 2.028.

d. For 1 - α = 0.95 and n = 52:

The degrees of freedom (df) = 52 - 1 = 51.

The upper-tail critical value (tα/2) is approximately 2.009.

e. For 1 - α = 0.90 and n = 9:

The degrees of freedom (df) = 9 - 1 = 8.

The upper-tail critical value (tα/2) is approximately 1.859.

Please note that the values provided above are approximations. To obtain more precise values, it is recommended to use a t-distribution table or statistical software.

Explanation:

To determine the upper-tail critical value (tα/2) for each given circumstance, we need to use the t-distribution table or a statistical software. The critical value is dependent on the significance level (α) and the degrees of freedom (df), which is equal to n - 1 for a sample size of n.

Using the t-distribution table or software, we can find the critical values for the given circumstances:

a. For 1 - α = 0.95 and n = 17:

The degrees of freedom (df) = 17 - 1 = 16.

The upper-tail critical value (tα/2) is approximately 2.120.

b. For 1 - α = 0.99 and n = 17:

The degrees of freedom (df) = 17 - 1 = 16.

The upper-tail critical value (tα/2) is approximately 2.583.

c. For 1 - α = 0.95 and n = 36:

The degrees of freedom (df) = 36 - 1 = 35.

The upper-tail critical value (tα/2) is approximately 2.028.

d. For 1 - α = 0.95 and n = 52:

The degrees of freedom (df) = 52 - 1 = 51.

The upper-tail critical value (tα/2) is approximately 2.009.

e. For 1 - α = 0.90 and n = 9:

The degrees of freedom (df) = 9 - 1 = 8.

The upper-tail critical value (tα/2) is approximately 1.859.

Please note that the values provided above are approximations. To obtain more precise values, it is recommended to use a t-distribution table or statistical software.