A counselor records the number of disagreements (per session)among couples during group counseling sessions.If the number of disagreements is distributed normally as 4.4 ± 0.4 (M ± SD)disagreements,then what proportion of couples disagree at least four times during each counseling session?
A) .3413
B) .1587
C) .8413
D) The probability is not listed in the unit normal table.

Question

Quizplus · Accepted Answer

To find the proportion of couples who disagree at least four times, we calculate the Z-score for 4 disagreements using the formula Z = (X - M) / SD, where X is 4, M is 4.4, and SD is 0.4. This gives Z = (4 - 4.4) / 0.4 = -1. The proportion of couples disagreeing less than four times corresponds to the area to the left of Z = -1 in the standard normal distribution, which is 0.1587. Therefore, the proportion disagreeing at least four times is 1 - 0.1587 = 0.8413.

A Counselor Records the Number of Disagreements (Per Session)among Couples