Question

TRUE FALSE

(.................) When testing the proportion, a ????? can be used provided the sample size is large.

(.................) The sample variance is an unbiased point estimator of population proportion.

(................) If a researcher wishes to determine whether there is evidence that the mean family income in the U.S. is greater than $35,000, then a two-sided test should be utilized.

(................) When sampling without replacement from a finite population such that the probability of a success, ?, is no longer constant from trial to trial, the data follow a hypergeometric distribution.

(................) On the average, 1.8 customers per minute arrive at any one of the checkout counters of a grocery store. A poisson distribution can be used to find out the probability that there will be no customers arriving at a checkout counter?

(................) Let random variable ? has a chi-square distribution with degress of freedom 5. Then the critical value that gives the right tail probability 0.90 is X5^2 = 1.610.

Answer 1

1) True

When testing the proportion, a can be used provided the sample size is large.

2) False

3) False

If a resercher wishes to determine whether there is evidence that the mean family income in U.S. is greater than $35,000, then a one-sided test should be utilised.

4) True

When sampling without replacement from a finite population such that the probability of a success, is no longer constant from trial to trial, the data follow a hypergeometric distribution.

5) True

On the average, 1.8 customers per minute arrive at any one of the checkout counters of a grocery store. A poisson distribution can be used to find out the probability that there will be no customers arriving at a checkout counter?

P(x=0) = e^-1.8 = 0.9193

Probability that there will be no customers arriving at a chechout counter is o.9193.

6) True

Let random variable x has chi- square distribution with degrees of freedom is 5 .

Then the critical value that gives the right tail probability 0.90 is X5^2 = 1.610.