In testing for the equality of two population variances, when the populations are normally distributed, the 5 level of significance has been used. To determine the rejection region, it will be necessary to refer to the F table corresponding to an upper-tail area of .05.
Indicate whether the statement is true or false
Q. 2Which of the following statements is false?
a. A moving average for a time period is the simple arithmetic average of the values in that time period and those close to it.
b. A value of the smoothing constant w close to 1 results in a very large smoothing, whereas a value of w close to zero results in very little smoothing.
c. The accuracy of the forecast with exponential smoothing decreases rapidly for predictions of the time series more than one period into the future.
d. A moving average forgets most of the previous time-series values and is considered a relatively crude method of removing the random variation.
Q. 3We use a t-test to determine whether two population variances are equal.
Indicate whether the statement is true or false
Q. 4In exponentially smoothed time series, the smoothing constant w is chosen on the basis of how much smoothing is required. In general, which of the following statements is true?
a. A small value of w such as w = 0.1 results in very little smoothing, while a large value such as w = 0.8 results in too much smoothing
b. A small value of w such as w = 0.1 results in too much smoothing, which a large value such as w = 0.8 results in very little smoothing
c. A small value of w such as w = 0.1 and a large value such as w = 0.8 may both result in very little smoothing
d. A small value of w such as w = 0.1 and a large value such as w = 0.8 may both result in too much smoothing
Q. 5If you are testing to see if a weight loss program is working, and you subtract the weights after - before for a group of 10 people, the alternative hypothesis is that the mean difference is ____________________ 0.
Fill in the blank(s) with correct word
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