Projecting winning candidate News coverage during a

recent election projected that a certain candidate would

receive 54.8% of all votes cast; the projection had a margin

of error of 3%.

a. Give a point estimate for the proportion of all votes

the candidate will receive.

b. Give an interval estimate for the proportion of all

votes the candidate will receive.

c. In your own words, state the difference between a

point estimate and an interval estimate.

z-score and confidence level

Which z-score is used in a

(a) 90%, (b) 98%, and (c) 99.9% confidence interval for a

population proportion?

Unemployment percentage

A statistician conducts

a study in order to estimate the proportion of families

living in a poor area of a city and having at least one un-

employed member. Calculate the sample size needed to

estimate it to within 0.05 with 95% confidence.

State the null and

alternative hypotheses

used to test each of the following claims:

a.

The mean reaction time is greater than 1.25

seconds.

b.

The mean score on that qualifying exam is less

than 335.

C.

The mean selling price of homes in the area is

not $230,000.

d. The mean weight of college football players is

no more than 210 lb.

e.

The mean hourly wage for a childcare giver is

at most $9.

-

For each of the following pairs of values,

state the decision that will occur and why.

a. p-value = 0.014, a = 0.02

b. p-value = 0.118, a = 0.05

c. p-value = 0.048 a = 0.05

d. p-value = 0.064, a = 0.10

8.113 According to the USA Today article "Laptops

inching closer to PCs in popularity" (February 6,

2005), the desktop PC era is ending and the age of

laptops has begun. A study by researcher Current

Analysis found that laptop prices fell to an ayerage of

$1211 during the 2004 December holidays. The

mean purchase price was thought to be $1240. The

researcher's finding is based on the purchase price

for a sample of 35 recently purchased laptops. As-

suming that o = $66.75, does the researcher have

sufficient evidence to make his claim or could his

sample results have realistically occurred by chance?

Describe the parameter of interest.

b. State the null and alternative hypotheses.

C.

Calculate the value for z* and find the p-value.

d.

State your decision

and conclusion using

a

= 0.001.