Answer:
[tex]t \approx 2.639[/tex]
Step-by-step explanation:
Given
[tex]\begin{array}{ccc}{} & {USA\ 1} & {Japan\ 2} & {\bar x} & {64.6} & {67.5} &{n} & {30} & {30} & {\sigma} & {4.0} & {4.5} \ \end{array}[/tex]
See attachment for data
Required
Determine the test statistic
The test statistic is calculated using:
[tex]t = \frac{\bar x_1 - \bar x_2}{\sqrt{\frac{\sigma_1^2}{n_1} + \frac{\sigma_2^2}{n_2}}}[/tex]
So, we have:
[tex]t = \frac{64.6 - 67.5}{\sqrt{\frac{4.0^2}{30} + \frac{4.5^2}{30}}}[/tex]
[tex]t = \frac{64.6 - 67.5}{\sqrt{\frac{16.00}{30} + \frac{20.25}{30}}}[/tex]
[tex]t = \frac{64.6 - 67.5}{\sqrt{\frac{16.00+20.25}{30}}}[/tex]
[tex]t = \frac{64.6 - 67.5}{\sqrt{\frac{36.25}{30}}}[/tex]
[tex]t = \frac{-2.9}{\sqrt{1.2083}}[/tex]
[tex]t = \frac{-2.9}{1.099}[/tex]
[tex]t \approx -2.639[/tex]
The absolute value is:
[tex]t \approx 2.639[/tex]
