Question

1.      One of the undersecretary of the Department of Labor and Employment (DOLE) claims that the average salary of Social worker is Php18, 000. A sample of 19 social worker’s salary has a mean of Php17, 350 and standard deviation of Php1, 230. Is there enough evidence to reject the undersecretary’s claim at 𝛼 = 0.01?

Answer 1

Solution:

$H_0:\mu=18000 \\ H_1:\mu\ne18000 \\ n=19 \\ \bar X=17350 \\\sigma=1230$

Test statistics: $\dfrac{\bar X-\mu}{\sigma/\sqrt n}= \dfrac{17350-18000}{1230/\sqrt {19}}=-2.303$

$t_{n-1}=t_{18}=2.878$

This is two-tailed test, so t-value is $\pm2.878$

Our test statistics -2.303 lies between t-values. So, we cannot reject null hypothesis.

Thus, we conclude that the average salary of Social worker is Php18, 000.