Question

Based on historical data, your manager believes that 43% of the company's orders come from first-time customers. A random sample of 243 orders will be used to estimate the proportion of first-time-customers. What is the probability that the sample proportion is between 0.2 and 0.39?

Answer 1

Answer:

Following are the solution to the question:

Step-by-step explanation:

$p = 0.43\\\\n = 243\\\\\sigma =\sqrt{\frac{p(1-p)}{n}}=\sqrt{\frac{0.43 (1 -0.43)}{243}}=0.0013$

z-score for $\hat{p}=0.2$ will be:

z score for will be:

$z=\frac{\hat{p}-p}{\sigma}=\frac{0.39 - 0.43}{0.0013}=-30.76$

$P(0.2$ using excel method to calculate the value.