Assume that the weights of all packages of a certain brand of cookies are normally distributed with a mean of 32 ounces and a st
andard deviation of 0.3 ounce. find the probability that the mean weight, x¯, of a random sample of 20 packages of this brand of cookies will be between 31.8 and 31.9 ounces.
1 answer:
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Solution :
The data is normally distributed.
The standard deviation is 18 days
Here the data is normally distributed and 54 days is 3 days of standard deviation.
Therefore, the percentage of the births that would be within the 54 days of the mean
length is given by :
= P( -3 < Z < 3)
= 0.9544
= 95 %
Therefore, about 95% of the births would be within 54 days of the men
length.