Respuesta :
Answer:
There is enough evidence to support the claim that the population mean of the students at this college is less than the recommended number of 8.4 hours.
Step-by-step explanation:
We are given the following in the question:
Population mean, μ = 8.4 hours
Sample mean, [tex]\bar{x}[/tex] = 7.72 hours
Sample size, n = 237
Alpha, α = 0.01
Sample standard deviation, s = 1.02 hours
First, we design the null and the alternate hypothesis
[tex]H_{0}: \mu = 8.4\text{ hours}\\H_A: \mu < 8.4\text{ hours}}[/tex]
We use one-tailed t test to perform this hypothesis.
Formula:
[tex]t_{stat} = \displaystyle\frac{\bar{x} - \mu}{\frac{s}{\sqrt{n}} }[/tex]
Putting all the values, we have
[tex]t_{stat} = \displaystyle\frac{7.72 - 8.4}{\frac{1.02}{\sqrt{237}} } = -10.2632[/tex]
Now, [tex]t_{critical} \text{ at 0.05 level of significance, 236 degree of freedom } = -2.3422[/tex]
Since, the calculated test statistic is less than the critical value, we fail to accept the null hypothesis and reject it. We accept the alternate hypothesis.
Conclusion:
Thus, there is enough evidence to support the claim that the population mean of the students at this college is less than the recommended number of 8.4 hours.