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(a) A statistician randomly sampled 100 observations and found X̄ = 106 and s = 35. Calculate the t statistic and p value for testing.     H0 : μ = 100 against HA : μ > 100.Carry out the test at the 1% level of significance.(b) Repeat part (a), with s = 25.(c) Repeat part (a), with s = 15.Repeat question 1 using HA : μ ≠ 100.

Question

(a) A statistician randomly sampled 100 observations and found X̄ = 106 and s = 35. Calculate the t statistic and p value for testing.     H0 : μ = 100 against HA : μ > 100.Carry out the test at the 1% level of significance.(b) Repeat part (a), with s = 25.(c) Repeat part (a), with s = 15.Repeat question 1 using HA : μ ≠ 100.

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Solution

(a) The t statistic is calculated as follows:

t = (X̄ - μ) / (s / √n)

where X̄ is the sample mean, μ is the population mean, s is the standard deviation, and n is the sample size.

So, t = (106 - 100) / (35 / √100) = 1.714

To find the p-value, we look up the t-value in the t-distribution table. However, since we are testing for μ > 100, we need to look at the one-tailed t-distribution. The p-value associated with t = 1.714 with 99 degrees of freedom is approximately 0.045.

Since the p-value is greater than the significance level of 0.01, we fail to reject the null hypothesis.

(b) If s = 25, then t = (106 - 100) / (25 / √100) = 2.4

The p-value associated with t = 2.4 with 99 degrees of freedom is approximately 0.009. Since the p-value is less than the significance level of 0.01, we reject the null hypothesis.

(c) If s = 15, then t = (106 - 100) / (15 / √100) = 4

The p-value associated with t = 4 with 99 degrees of freedom is approximately 0.0001. Since the p-value is much less than the significance level of 0.01, we reject the null hypothesis.

For HA : μ ≠ 100, we would use a two-tailed test. The calculations for the t statistic would be the same, but we would double the p-value. If the doubled p-value is less than the significance level, we would reject the null hypothesis.

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Similar Questions

In carrying out a one-sample t-test for a mean, the hypotheses H0:mu=10 against HA:mu>10 were tested.A sample of size 21 was used, giving a t-statistic of 2.00.Determine the P-value associated with this test.

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