The random sample size is .
of adult americians had obtained bacheors degree, thus .
The value of .
The value of mean is .
Substitute and .
The value is .
The standard deviation is .
Substitute , and .
.
The standard deviation is .
Find the probability .
.
Find the corresponding -values for and .
The value of is .
For , and
.
For , and .
.
The approximate area corresponds to is .
Therefore, the probability that in a random sample of people , between is .
The probability that in a random sample of people , between is .
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