Question

1. For the standard normal distribution, compute Z_0.69. Use Excel and round the answer to two decimal places.
2. Consider the following test performed with the level of significance 0.01: A random sample of size 28 is obtained from a normally distributed population. The population standard deviation is equal to 3.6. The sample mean happened to be 24. For this hypothesis test, what will be the critical value (the relevant z-alpha)?  Round the answer to three decimal places.
3. A probability distribution of all possible sample proportions of a given sample size is called the sampling distribution of the sample ----------
4. Select the false statement.

a. When t-numbers are used for computing the width of a confidence interval, the corresponding Student's t-distribution follows (n-1) degrees of freedom, where n is the sample size.

b. One should use z-numbers when estimating the population proportion.

c. When one knows the standard deviation of the population, one must use t-numbers to determine the width of a confidence interval.

d. If all other relevant variables are kept the same, than the bigger the sample size, the narrower the confidence interval is.

Answer 1