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In each of the following cases, do you think the sample size is large enough to use the normal distribution to make a test of hypothesis about the population proportion? Explain why or why not. a. \(n=30\) and \(p=.65\) b. \(n=70\) and \(p=.05\) c. \(n=60\) and \(p=.06\) d. \(n=900\) and \(p=.17\)

Short Answer

Expert verified
Normal distribution can be applied for cases a and d, not for cases b and c.

Step by step solution

01

Calculate np and n(1-p) for case a

We start with case a. The given values are \(n=30\) and \(p=.65\). Calculate \(np = 30 * 0.65 = 19.5\) and \(n(1-p) = 30 * (1-0.65) = 10.5\).
02

Assess Normal Approximation for case a

Since both \(np = 19.5\) and \(n(1-p) = 10.5\) are greater than 5, it is safe to apply the normal approximation for case a.
03

Repeat Steps 1 and 2 for other cases

Repeat the process followed in Steps 1 and 2 for the other cases. For case b, we have \(np = 70*0.05 = 3.5, n(1-p)=66.5\). For case c, we have \(np = 60*0.06 = 3.6, n(1-p)=56.4\). And for case d, \(np = 900*0.17 = 153, n(1-p)=747\).
04

Conclude

Based on the computations, the normal approximation will not be applicable for cases b and c, as their respective \(np\) values are less than 5. However, it will be safe to apply for cases a and d as both their \(np\) and \(n(1-p)\) values are greater than 5.

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