Adistribution of scores is approximately normal with a mean of 78 and a standard deviation of 8.6. which of the following equations can be used to find the score x above which 33 percent of the scores fall?
(a) 0.44=1.78
(b) 0.67= 78
(c) 0.33= -78
(d) 0.44=1.78
(e) 0.67-8.68

The correct answer is (D)

Step-by-step explanation:

If we check the value in the Normal Distribution table, the x score that falls above 33% is given by:

P(z>x)=0.33

1 - P(z≤x)=0.33

1 - 0.33=P(z≤x)

0.67=P(z≤x)⇒ z=0.44

Also

z=(x-μ)/σ

where:

μ: mean of the distribution

σ: standard deviation of the distribution

Hence,

0.44=(x-78)/8.6

about 0.75 hours

step-by-step explanation: