68 percent within one standard deviation from the mean.
b) 50+34=84 percent (within one standard deviation of mean, or 34 percent on each side)
c. 50+95/2=50+47.5=98
d. 50-34
and so forth. Some are called above in percentage, or relative frequency. Relative frequency is percentage divide by 100
if percentage is 14 percent, relative frequency is .14
http://davidmlane.com/hyperstat/z_table.html
Using the 68-95-99.7 rule:
Assume that a set of test scores is normally distributed with a mean of 100 and a standard deviation of 20. Use the 68-95-99.7 rule to find the following quantities:
a. Percentage of scores less than 100
b. Relative frequency of scores less than 120
c. Percentage of scores less than 140
d. Percentage of scores less than 80
e. Relative frequency of scores less than 60
f. Percentage of scores greater than 120
1 answer
2 answers