You are tasked with testing a company's claim that its new test preparation book increases the chance of passing an exam to more than 60%. You took a random sample of 30 people who used the book, and found that 25 people passed the exam. From the above data, test the validity of the company's claim (i.e., answer the questions below). Use a significance level of 5% (i.e.,=0.05 ).

a) What are 0 and1?What tailed test is this?

b) What is the value of the Test Statistic?(3 pts)

c) What is the critical value for this test?(3 pts)

d) What is the P-value?(3 pts)

e) Would you "reject" or "fail to reject" 0?Why?

f) Summarize your conclusion in Plain English (slide #12, Ch 8 slides)

g) Would your conclusion remain the same at =0.01? Why?

The prices (in dollars) for a particular model of a digital camera is shown below for 6 randomly selected online retailers:

99914991997119912491129

You want to estimate the true mean () price of this particular model with 95% confidence.

(a) What is the best Point Estimate for given the above data?

(b) What is the margin of error ()?

(c) Write down the 95% CI for (Type answer in the form:xxx < mu < yyy)

(d) From the above CI, can you justify the claim that the mean price is more than $1400 ?

The average family size in the US is reported to be 3.1. The mayor of a California town claims that the average family size in his town is less than the National average. To test this claim, a statistician collected data on 20 families in that town and found that the sample average () and standard deviation () were 2.9 and 0.3, respectively. At a 5% significance level (i.e., =0.05) the mayor's claim be justified?

HINT:

EITHER perform a 4-step Hypothesis Test OR determine the 90% CI.[not 95% CI]

Show some results, e.g., if doing hypothesis testing, show the Test Statistic, Critical Value, P-value etc.; OR if doing CI, show the values of LCL and UCL

Write down your conclusion in plain English