Statistics Help. In a pulse rate research, a simple random sample of 400 men results in a mean of 80 beats per minute, and a standard deviation of 10.8 beats per minute. Based on the sample results, the researcher concludes that the pulse rates of men have a standard deviation greater than 10 beats per minutes. Use a 0.05 significance level to test the researcher's claim.
(a) Identify the null hypothesis and alternative hypothesis.
(b) Determine the test statistic.
(c) Determine the P-value for this test.
(d) Is there sufficient evidence to support the researcher's claim? Explain.