It's about tatistics. More detail please check the attach. 

 

 

1. A reporter wishes to estimate the percent of men at a women’s-rights rally. In a
random sample of 1200 people at the rally, he observed 300 men.
a. The 300 is the _______ value for the number of men in the sample.
Options:
1. expected (ii) observed
b. The SD of the box is _______ 0.25 0.75 .
Options:
1. exactly equal to (ii) estimated from the data as
c. Find a 95% confidence interval for the percentage of men at the rally.
(20 points)
2. In a certain town, there are 4,000 registered voters, of whom 1,600 are Democrats.
A survey organization is about to take a random sample of 100 registered voters.
a. There is about a 50-50 chance that the percentage of Democrats in the
sample will be bigger than _____.
b. Find the expected value for the sample percentage,
c. Find the standard error for the sample percentage.
d. Find the chance that 30% or more of the people in sample are Democrats.
e. True or false: If a large sample were taken, the standard error for the
sample percentage would have been smaller.
(20 points)
3. 400 draws are made at random with replacement from the box:
2 4 6
a. What is the expected value and SE for the average of 400 draws?
b. What is the expected value and SE for the sum of 400 draws?
c. If the sum of 400 draws is 1500, is this reasonable?
(20
points)
4. A simple random sample of 625 households is surveyed from a city. On the
average, there are 2.30 persons per sample household with SD of 1.75. Find 95%
confidence interval for the average household size in the city.
(20 points)
5. A book was published entitled: “One Million Random Digits.” In it there are
listed one million (1,000,000) digits, each of course being from 0 to 9, inclusive.
Suppose that there were 100,907 fives among the million digits published.
How many fives were expected if the selection process were truly random? Is this
result consistent with a random model?
(20 points) 1

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• 1492760585-Math.doc