1.The tails of the theoretical normal curve

a.intersect with the horizontal axis between the 4th and 5th standard deviation.

b.intersect with the horizontal axis beyond the 5th standard deviation.

c.never touch the horizontal axis.

d.maintain the same distance above the horizontal axis beyond the 3rd standard deviation.

2.On all normal curves the area between the mean and 2 standard deviations will be

a.about 34% of the total area.

b.about 95% of the total area.

c.less than 50% of the total area.

d.about 68% of the total area.

3.Assuming a normal distribution of 1000 cases, how many cases will be within 1 standard deviations of the mean?

a.At least 500

b.About 3

c.About 680

d.It is impossible to estimate