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1. True or False (and explain why if False) _______ The sampling distribution of

ID: 3152467 • Letter: 1

Question

1. True or False (and explain why if False)

_______                   The sampling distribution of the sample mean is always EXACTLY Normal

_______                   If you increase the Type I error rate you increase your power.

______                   The t-distribution is symmetric around zero.

______                   As you decrease your confidence level when calculating a confidence interval, you make your confidence interval wider

______                   The sample mean is exactly the same as the true mean of the population

______                   If you increase the type I error rate, , you are more likely to not reject the null hypothesis

______                   The standard error increases if the sample size increases

______                   You tend to reject the null hypothesis when you have large (>.05) p-values

______                If you find that zero is not included in a 95% confidence interval for the mean difference between two populations that mean you would not reject the null hypothesis of no difference at a 0.05 significance level of a two-sided test.

_______              The p-value is a probability.

Explanation / Answer

The sampling distribution of the sample mean is always EXACTLY Normal. False

The sampling distribution of the sample mean is appromattely normal when sample size is greater than 30.

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If you increase the Type I error rate you increase your power. true

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The t-distribution is symmetric around zero. true

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As you decrease your confidence level when calculating a confidence interval, you make your confidence interval wider. False

As confidence level decreases, critical value also decreases so the confidence interval become narrower.

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The sample mean is exactly the same as the true mean of the population. False

The sample mean is an unbiased estimator of the true mean of the population.

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If you increase the type I error rate, , you are more likely to not reject the null hypothesis. False

If you increase the type I error rate, , you are more likely to reject the null hypothesis.

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The standard error increases if the sample size increases. False

The standard error decreases if the sample size increases beucase sample size come into denominator of the standard error.

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You tend to reject the null hypothesis when you have large (>.05) p-values. False

if p-value of greater than 0.05 (level of significance), we fail to reject the null hypothesis.

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If you find that zero is not included in a 95% confidence interval for the mean difference between two populations that mean you would not reject the null hypothesis of no difference at a 0.05 significance level of a two-sided test. False

If zero is not included in a 95% confidence interval, we reject the null hypothesis of no difference at a 0.05 significance level of a two-sided test.

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The p-value is a probability. True