Question

The mean age at first marriage for respondents in a survey is 23.33, with a standard deviation of 6.13. The Z score associated with a particular age at first marriage is .35. If the proportion of the area between this particular age at first marriage and the mean is 0.14, what proportion of respondents experienced their first marriage earlier than this age? Illustrate your answer in a normal curve.

Answer 1

2

Here the shaded area indicates the P(z < 0.35)

we know P(0 < z < 0.35) = 0.14

required probability = 0.14 + 0.5 = 0.64

Hence 0.64 respondents experienced their first marriage earlier than this age