Suppose that you are testing the hypotheses H0: p=0.18 vs. HA:
p=/ 0.18. A sample of size 150 results in a sample proportion of
0.25.
a) Construct a 99% confidence interval for p.
b) Based on the confidence interval, can you reject H0 at a
=0.01? Explain.
c) What is the difference between the standard error and
standard deviation of the sample proportion?
d) Which is used in computing the confidence interval?
Find the following probabilities for the standard normal random
variable z:
(a) P(−0.76<z<0.75)=
(b) P(−0.98<z<1.36)=
(c) P(z<1.94)=
(d) P(z>−1.2)=
2.
Suppose the scores of
students on an exam are Normally distributed with a mean of 480 and
a standard deviation of 59. Then approximately 99.7% of the exam
scores lie between the numbers ---- and
-----. ??
Hint: You do not need to use table E for this problem.
Consider the following hypothesis test:
H0: p ≥ 0.75
Ha: p < 0.75
A sample of 300 items was selected. Compute the p-value and
state your conclusion for each of the following sample results. Use
α = .05.
Round your answers to four decimal places.
a. p = 0.67 p-value _____?
b. p = 0.75 p-value _____?
c. p = 0.7 p-value _____?
d. p = 0.77 p-value _____?
Consider the following hypothesis test:
H0: p ≥ 0.75
Ha: p < 0.75
A sample of 300 items was selected. Compute the p-value
and state your conclusion for each of the following sample results.
Use = .05.
Round your answers to four decimal places.
b. = 0.74
p-value is
c. = 0.78
p-value is
67. Suppose that P(B) = 0.4, P(A|B) = 0.1 and P(A|B^c) =
0.9
(a) Calculate P(A)
(b) Calculate P(A|B)
71. Suppose a couple decides to have three children.
Assume that the sex of each child is independent, and the
probability of a girl is 0.48, the approximate figure in the
US.
(a) How many basic outcomes are there for this
experiment? Are they equally likely?
(b) What is the probability that the couple has at least
one girl?
104. A...
Let P(A) = 0.40, P(B) = 0.20, P(C) = 0.50, P(D) = 0.30, P(A ∩ B)
= 0.15, P(A | C) = 0.60, P(B | C) = 0.20, P(B ∩ D) = 0.10, and C
and D are mutually exclusive.
Find ...
a. P(C ∩ D)
b. P(C U D)
c. P(B ∩ C)
d. Which one of the following pairs is a pair of statistically
independent events? (A and C) (B and D) (B and C) (C and D)