This preview shows pages 1–2. Sign up to view the full content.
1.
A large normally distributed population has a mean of 150 and a std. dev.
Of 12
a. Find the probability that a random selected score is between 150 and 157.
b. If a sample of size n = 100 is randomly selected, find the probability that the
sample mean will be between 150 and 157.
a. Z value=
So z value for 150=z1=150150/12=0
And z value for 157=z2=157150/12=0.58
So we have to find p(z1<z<z2)=p(0<z<0.58)=0.7190
b.
The normal dist. Is itself a case of increasing no. of N. As N increases in binomial dist. It
changes to normal dist.
The only effect of increasing the sample size is that the sample will stick to each other with a
less distance and follow the same normal dist. The samples will be more closely to each
other. But no effect will be on prob.
2.
At the
α
=0.05 significance level, test the claim that the proportion of fraudulent credit card
applicants is more than 0.23.
A sample of n=1200 reveals that 26.3% of them are fraudulent.
Z Test of Hypothesis for the
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview. Sign up
to
access the rest of the document.
This note was uploaded on 01/31/2012 for the course QM 2113 taught by Professor Kent during the Fall '11 term at ASU.
 Fall '11
 Kent

Click to edit the document details