SOLUTION: Based on historical data , your manager believes that 31% of the company's orders come from first-time customersA random sample of 129 orders will be used to estimate the proportio

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Question 1195484: Based on historical data , your manager believes that 31% of the company's orders come from first-time customersA random sample of 129 orders will be used to estimate the proportion of first-time-customers . What is the probability that the sample proportion is between 0.26 and 0.437
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
129*0.26=33.54 use 33.5
129*0.437=56.373 so use 56.5 continuity correction factor.
the mean is np or 129*0.31=39.99.
variance is np(1-p)=24.3939
sd is sqrt(24.3939)=4.94
want z=(56.5-39.99)/4.94
=16.51/4.94
=+3.34
z=(33.5-39.99)/4.94=-1.01
probability of z in that range is 0.8433