High School

A test of significance is performed to determine if the mean SAT score at a local high school is greater than the national average of 1000. A random sample of 50 students at the school was selected, with a sample mean SAT score of 1050 and a standard deviation of 100.

What is the test statistic for this hypothesis test?

Answer :

The test statistic for this hypothesis test is approximately z = 3.5355.

To calculate the test statistic for this hypothesis test, we can use the formula for the z-test for a population mean:

[tex]\[ z = \frac{{\bar{x} - \mu}}{{\frac{{\sigma}}{{\sqrt{n}}}}} \][/tex]

where:

- [tex]\( \bar{x} \)[/tex] is the sample mean (1050 in this case),

-[tex]\( \mu \)[/tex] is the population mean (1000, the national average),

-[tex]\( \sigma \)[/tex] is the population standard deviation (100 in this case), and

- [tex]\( n \)[/tex] is the sample size (50 in this case).

Substituting the given values into the formula, we get:

[tex]\[ z = \frac{{1050 - 1000}}{{\frac{{100}}{{\sqrt{50}}}}} \][/tex]

[tex]\[ z = \frac{{50}}{{\frac{{100}}{{\sqrt{50}}}}} \][/tex]

[tex]\[ z = \frac{{50}}{{10 \sqrt{2}}} \][/tex]

z ≈ [tex]\frac{{50}}{{14.1421}}[/tex]

z ≈ 3.5355

Therefore, the test statistic for this hypothesis test is approximately z = 3.5355.