Answer:
Step-by-step explanation:
Let X be the length of pregnancy.
X is N(268, 15)
a) Prob of pregnancy lasting 307 days or longer
= P(X>307) =
=0.5-0.4953
=0.0047
b) Lowest 2% is 2nd percentile
Z=-2.55
X score = 268-2.55(15)
= 229.75 days
If length of days >230 days then it is not premature.
Answer:
4/5 hour . . . . 48 minutes
Step-by-step explanation:
In hours, the total time is ...
... 1/10 + 1/5 + 1/2 = 1/10 + 2/10 + 5/10
... = (1+2+5)/10 = 8/10
... = 4/5
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You can have a calculator add these numbers for you. Most will report the result as a decimal. There are fraction calculators on-line, if your graphing calculator does not have a fraction display mode.
If you want minutes, multiply the fraction (or decimal) by 60 minutes.
