Suppose the scores on an exam are normally distributed with a mean μ = 75 points, and standard deviation σ = 8 points. The instr

Question

3 years ago

11

Suppose the scores on an exam are normally distributed with a mean μ = 75 points, and standard deviation σ = 8 points. The instr

uctor wanted to "pass" anyone who scored above 69. What proportion of exams will have passing scores?
(a) .25 (b) .75 (c) .2266 (d) .7734 (e) -.75

Mathematics

1 answer:

galben [10] · Answer 1 · 2022-05-11T22:59:06+03:00

Answer:

(d): 0.7734

Step-by-step explanation:

Using the normcdf( statistical function built into my old TI 83-Plus calculator, I find that the area under the standard normal curve from the extreme left to the value 69 is 0.2266. Thus, about 0.2266 of students would fail and

1.000-0.2266, or 0.7734 would pass. This corresponds to Answer (d).