Answer:
66.48% of full-term babies are between 19 and 21 inches long at birth
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Mean length of 20.5 inches and a standard deviation of 0.90 inches.
This means that 
What percentage of full-term babies are between 19 and 21 inches long at birth?
The proportion is the p-value of Z when X = 21 subtracted by the p-value of Z when X = 19. Then
X = 21



has a p-value of 0.7123
X = 19



has a p-value of 0.0475
0.7123 - 0.0475 = 0.6648
0.6648*100% = 66.48%
66.48% of full-term babies are between 19 and 21 inches long at birth
Step-by-step explanation:
.19 = 19/100
.864 = 86.4/100
.5348 = 53.48 /100
I multiplied the decimal by 100 to get what it was before which is the same as moving two decimal places to the right and divided by 100
if any confusion ask
Answer:
the last one
Step-by-step explanation:
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Answer:
is this correct. I hope it is