In Exercises 5 and 6. determine whether you can use a normal distribution to approximate the binomial distribution. If you can, use the normal distribution to approximate the indicated probabilities and sketch their graphs. If you cannot, explain why and use a binomial distribution to find the indicated probabilities. 5. Sixty-nine percent of U.S. college graduates expect to stay at their first employer for three or more years. You randomly select 18 U.S. college graduates and ask them whether they expect to stay at their first employer for three or more years. Find the probability that the number who expect to stay at their first employer for three or more years is (a) exactly 10. (b) less than 7. and (c) at least 15. Identify any unusual events. Explain. (Source: Accenture)
In Exercises 5 and 6. determine whether you can use a normal distribution to approximate the binomial distribution. If you can, use the normal distribution to approximate the indicated probabilities and sketch their graphs. If you cannot, explain why and use a binomial distribution to find the indicated probabilities. 5. Sixty-nine percent of U.S. college graduates expect to stay at their first employer for three or more years. You randomly select 18 U.S. college graduates and ask them whether they expect to stay at their first employer for three or more years. Find the probability that the number who expect to stay at their first employer for three or more years is (a) exactly 10. (b) less than 7. and (c) at least 15. Identify any unusual events. Explain. (Source: Accenture)
Solution Summary: The author explains that the normal distribution can be used to approximate the binomial distribution. The sample size is n=18 and the number of college graduates expect to stay at first employer for three or more years is 0.69
In Exercises 5 and 6. determine whether you can use a normal distribution to approximate the binomial distribution. If you can, use the normal distribution to approximate the indicated probabilities and sketch their graphs. If you cannot, explain why and use a binomial distribution to find the indicated probabilities.
5. Sixty-nine percent of U.S. college graduates expect to stay at their first employer for three or more years. You randomly select 18 U.S. college graduates and ask them whether they expect to stay at their first employer for three or more years. Find the probability that the number who expect to stay at their first employer for three or more years is (a) exactly 10. (b) less than 7. and (c) at least 15. Identify any unusual events. Explain. (Source: Accenture)
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…
Let X = the time between two successive arrivals at the drive-up window of a local bank. If X has an exponential distribution with λ = 1, (which is identical to a standard gamma distribution with α = 1), compute the following. (If necessary, round your answer to three decimal places.)
(a) the expected time between two successive arrivals
(b) the standard deviation of the time between successive arrivals
(c)
P(X ≤ 1)
(d)
P(2 ≤ X ≤ 4)
You may need to use the appropriate table in the Appendix of Tables
Chapter 5 Solutions
Elementary Statistics: Picturing the World (7th Edition)
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Discrete Distributions: Binomial, Poisson and Hypergeometric | Statistics for Data Science; Author: Dr. Bharatendra Rai;https://www.youtube.com/watch?v=lHhyy4JMigg;License: Standard Youtube License