Iq scores for adults age 20 to 34 years are normally distributed according to n(120, 20). in what range does the middle 68% of people in this group score on the test? 100−140 120−160 80−120 80−140 120−160

100−140

Explanation:

The normal distribution has two parameters:

The mean

The standard deviation .

It can be called .

The 68-95-99.7 rule indicates that:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviations of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

N(120,20).

This means that the middle 68% of people in this group score on the test are in the range of 120-20 = 100 to 120+20 = 140.

it would take 95 years for that supernova to be visible on earth, so the year would be about 2113. i hope i did my calculation right.