Hypothesis Testing Using Rejection Region(s) In Exercises 37–42, (a) identify the claim and state H 0 and H a , (b) find the critical value(s) and identify the rejection region(s), (c) find the standardized test statistic z, (d) decide whether to reject or fail to reject the null hypothesis, and (e) interpret the decision in the context of the original claim. 38. High School Graduation Rate An education researcher claims that the mean high school graduation rate per state in the United States is 80%. You want to lest this claim. You find that a random sample of 30 states has a mean high school graduation rate of 82%. Assume the population standard deviation is 5.1%. At α = 0.05, do you have enough evidence to support the researcher’s claim? (Source: U.S. Department of Education)
Hypothesis Testing Using Rejection Region(s) In Exercises 37–42, (a) identify the claim and state H 0 and H a , (b) find the critical value(s) and identify the rejection region(s), (c) find the standardized test statistic z, (d) decide whether to reject or fail to reject the null hypothesis, and (e) interpret the decision in the context of the original claim. 38. High School Graduation Rate An education researcher claims that the mean high school graduation rate per state in the United States is 80%. You want to lest this claim. You find that a random sample of 30 states has a mean high school graduation rate of 82%. Assume the population standard deviation is 5.1%. At α = 0.05, do you have enough evidence to support the researcher’s claim? (Source: U.S. Department of Education)
Hypothesis Testing Using Rejection Region(s)In Exercises 37–42, (a) identify the claim and state H0and Ha, (b) find the critical value(s) and identify the rejection region(s), (c) find the standardized test statistic z, (d) decide whether to reject or fail to reject the null hypothesis, and (e) interpret the decision in the context of the original claim.
38. High School Graduation Rate An education researcher claims that the mean high school graduation rate per state in the United States is 80%. You want to lest this claim. You find that a random sample of 30 states has a mean high school graduation rate of 82%. Assume the population standard deviation is 5.1%. At α = 0.05, do you have enough evidence to support the researcher’s claim? (Source: U.S. Department of Education)
Features Features Normal distribution is characterized by two parameters, mean (µ) and standard deviation (σ). When graphed, the mean represents the center of the bell curve and the graph is perfectly symmetric about the center. The mean, median, and mode are all equal for a normal distribution. The standard deviation measures the data's spread from the center. The higher the standard deviation, the more the data is spread out and the flatter the bell curve looks. Variance is another commonly used measure of the spread of the distribution and is equal to the square of the standard deviation.
A 12-inch bar that is clamped at both ends is to be subjected to an increasing amount of stress until it snaps. Let Y = the distance from the left end at which the break occurs. Suppose Y has the following pdf.
f(y) =
{
(a) Compute the cdf of Y.
F(y) =
0
0
y
-옴)
0 ≤ y ≤ 12
1-
12
y 12
Graph the cdf of Y.
F(y)
1.0
0.8
0.6
0.4
0.2
y
2
6
8
10
12
F(y)
F(y)
F(y)
1.01
1.0ㅏ
1.0
0.8
0.6
0.4
0.2
0.8
0.8
0.6
0.4
ཨཱུ སྦེ
0.6
0.4
0.2
2
4
6
8
10
12
(b) Compute P(Y ≤ 5), P(Y > 6), and P(5 ≤ y ≤ 6). (Round your answers to three decimal places.)
P(Y ≤ 5) =
P(Y > 6) =
P(5 ≤ y ≤ 6) =
(c) Compute E(Y), E(y²), and V(Y).
E(Y) =
in
E(Y2)
v(x) =
in 2
2
2
4
6
8
10
12
y
2
4
6
8
10
12
A restaurant serves three fixed-price dinners costing $12, $15, and $20. For a randomly selected couple dining at this restaurant, let X = the cost of the man's dinner and Y = the cost of the woman's dinner. The joint pmf of X and Y is given in the following table.
p(x, y)
15
y
12
20
12
0.05 0.10
0.35
x
15
0.00 0.20
0.10
20
0.05 0.05
0.10
(a) Compute the marginal pmf of X.
x
12
Px(x)
Compute the marginal pmf of Y.
y
Pyly)
12
15
20
15
20
(b) What is the probability that the man's and the woman's dinner cost at most $15 each?
(c) Are X and Y independent? Justify your answer.
X and Y are independent because P(x, y) = Px(x) · Py(y).
X and Y are not independent because P(x, y) =Px(x) · Pyly).
X and Y are not independent because P(x, y) * Px(x) · Py(y).
X and Y are independent because P(x, y) * Px(x) · Py(y).
(d) What is the expected total cost, in dollars, of the dinner for the two people?
$
(e) Suppose that when a couple opens fortune cookies at the conclusion of the meal, they find the…
Chapter 7 Solutions
Elementary Statistics: Picturing the World (7th Edition)
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Hypothesis Testing and Confidence Intervals (FRM Part 1 – Book 2 – Chapter 5); Author: Analystprep;https://www.youtube.com/watch?v=vth3yZIUlGQ;License: Standard YouTube License, CC-BY