Week 4 Test - Results
Attempt 1 of 2
Written Sep 28, 2025 10:57 PM - Sep 28, 2025 11:45 PM
Attempt Score - 80 %
Overall Grade (Highest Attempt) - 80 %
Question 1 point
The length of a human pregnancy is normally distributed with a mean of 270
days with a standard deviation of 8 days. How many days would a pregnancy
last for the shortest 15%? Round answer to 2 decimal places. Answer:
___261.71___
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In Excel,
=NORM.INV(0.15,270,8)
Question 2 point
Find P(Z > -.98). Round answer to 4 decimal places. Answer: ___0.8365___
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In Excel,
=1- NORM.S.DIST(-.98,TRUE)
Question 3 point
Find P(-1.25 < Z < 1.99). Round answer to 4 decimal places. Answer:
___0.8711___
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In Excel,
=NORM.S.DIST(1.99,TRUE)-NORM.S.DIST(-1.25,TRUE)
Question 4 point
Find the probability that
χ
falls in the shaded area.
Attempt 1 of 2
Written Sep 28, 2025 10:57 PM - Sep 28, 2025 11:45 PM
Attempt Score - 80 %
Overall Grade (Highest Attempt) - 80 %
Question 1 point
The length of a human pregnancy is normally distributed with a mean of 270
days with a standard deviation of 8 days. How many days would a pregnancy
last for the shortest 15%? Round answer to 2 decimal places. Answer:
___261.71___
Hide question 1 feedback
Feedback
In Excel,
=NORM.INV(0.15,270,8)
Question 2 point
Find P(Z > -.98). Round answer to 4 decimal places. Answer: ___0.8365___
, Hide question 2 feedback
Feedback
In Excel,
=1- NORM.S.DIST(-.98,TRUE)
Question 3 point
Find P(-1.25 < Z < 1.99). Round answer to 4 decimal places. Answer:
___0.8711___
Hide question 3 feedback
Feedback
In Excel,
=NORM.S.DIST(1.99,TRUE)-NORM.S.DIST(-1.25,TRUE)
Question 4 point
Find the probability that
χ
falls in the shaded area.
