Standard Normal Model

Question

According to the 68-95-99.7 rule, within what bounds will we expect 95% of values lie if we have a mound shaped distribution with a mean of 40 and a variance of 9? 

34, 46 

37, 43 

22, 58 

31, 49 

13, 67 

Question

In a standard Normal model, what value of Z cuts off the highest 3% of values? 

0.84 

1.88 

0.618 

0.242 

0.382 

Question

Find the standard deviation of a Normal model with mean 0.50 if 20% of values are BELOW 

0.38. 

0.84 

0.2 

0.1 

0.14 

1.43

Question

What is meant by the sampling distribution of the sample proportion? 

The distribution of possible samples that we could take, each of the same size. 

The distribution of the sample values from taking one very large sample. 

The sample proportion that would be likely to occur from a random sample providing the sample is large. 

The sample proportion that would be likely to occur from a random sample of any size. 

The distribution of possible values of the sample proportion, when we take repeated samples each of the same size, and calculate the proportion from each one. 

Question

A random sample of size 100 is drawn from a population with mean 48 and variance 25. What is the variance of the sample mean? 

2 

0.25 

20 

4 

0.4