STAT200 Homework Solution

Question: #1246

You draw two cards from a deck, what is the probability that:
both of them are face cards (king, queen, or jack)?
you draw two cards from a deck and both of them are hearts

Assume adults have IQ scores that are normally distributed with a mean of 100 and a standard deviation of 15.

Find the probability that a randomly selected adult has IQ < 115
Find the probability that a randomly selected adult has IQ > 70
Find P_30, which is the IQ separating the bottom 30% from the top 70%

a. When would the mean grade in a class on a final exam be considered a statistic?

b. When would it be considered a parameter?

c.. Define bias in terms of expected value.

Is it possible for a statistic to be unbiased yet very imprecise? Can it be accurate but biased?

4.a. Why is a 99% confidence interval wider than a 95% confidence interval?

b. When you construct a 95% confidence interval, what are you 95% confident about?

5.My parents lived in Florida and wanted to know the probability of winning the Florida Fantasy 5 if they bought one ticket. They had to pick the five winning numbers from 1-

36. Each randomly selected number is different and order doesn’t matter. What is the Probability of their winning?

6.In a study of families with children with disabilities, group of 6 US households wererandomly selected. In the table below, the random variable x represents the number of households among 6 that had a child with a disability living there.

x	P(x)
0	0.539
1	0.351
2	0.095
3	0.014
4	0.001
5	0+
6	0+

Is this a probability distribution?
What is the mean?
What is the standard deviation?

7.Ten peas are generated from parents having the green/yellow pair of genes so there is a 75% probability that an individual pea will have a green pod. Find the probability that among the 10 offspring peas, at least 9 have green pods. Is this unusual? Explain.

8. Find the critical value

a. Z_0.02

b. Z_0.01

c. Z_0.10

Solution: #1237

STAT200 Homework Solution

If the class is considered as a population itself, then the mean grade in a class on a final exam is considered a statistic.Yes, it is possible for a...