A) Distinguish between nonprobability and probability samples and compare their advantages and disadvantages.
Which are used for qualitative and which for quantitative studies?
1) Identify and describe two types of non-probability sampling methods and two types of probability sampling methods
2) Discuss how sample size requirements differ between qualitative and quantitative studies.
B) Identify phenomena/variables that lend themselves to self-reports, observation, and biophysiologic measurement and discuss each of these types of data collection.
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Chapter 6.1 review questions, #23 part B. In order to find the probability of a fourth or fifth live birth, I have to multiple the probability of a fourth birth and the probability of a fifth birth. This would be 0.096 x 0.047. My calculator is saying the answer is 0.004512. However, Chegg textbook solutions and the book says the answer is 0.143, which would be the two probabilities being added together. I'm not sure which is wrong; is the answer wrong or is the operation wrong?
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In a survey of a group of men, the heights in the 20-29 age group were normally distributed, with a mean of
69.6 inches and a standard deviation of 2.0 inches. A study participant is randomly selected. a) Find a probability that a study participant has a height that is less than 66 inches. b) Find the probability that a study participant has a height that is between 66 and 72. c) Find the probability that a study participant has a height that is more than 72 inches. d)
inches.
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Suppose that you and two friends go to a restaurant, which last month filled approximately 77 % of the orders correctly. Complete parts (a) through (d) below.
a. What is the probability that all three orders will be filled correctly?
b. What is the probability that none of the three orders will be filled correctly?
c. What is the probability that at least two of the three orders will be filled correctly?
d. What are the mean and standard deviation of the binomial distribution used in a through c? Interpret these values
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1. Five cards are dealt at random from a well-shuffled deck of 52 playing cards. Find the probability that: a. All are spades. b. Exactly two are hearts. c. Exactly three are clubs. d. All are red. e. At least one card is ace. 2. Tossing a coin 15 times find the probability of getting exactly 4 tails. 3. Find the probability of getting at least 4 tails for tossing a coin 15 times
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A survey of adults ages 18-29 found that 83%
use the Internet. You randomly select 108 adults ages 18-29 and ask them if they use the Internet.
(a) Find the probability that exactly 86 people say they use the Internet.
(b) Find the probability that at least 86 people say they use the Internet.
(c) Find the probability that fewer than 86 people say they use the Internet.
(d) Are any of the probabilities in parts (a)-(c) unusual? Explain.
In: Statistics and Probability
The time until failure for an electronic switch has an exponential distribution with an average time to failure of 4 years, so that λ =
| 1 |
| 4 |
= 0.25. (Round your answers to four decimal places.)
(a)
What is the probability that this type of switch fails before year 3?
(b)
What is the probability that this type of switch will fail after 5 years?
(c)
If two such switches are used in an appliance, what is the probability that neither switch fails before year 7?
In: Statistics and Probability
Assume the average price for a movie is $10.16. Assume the population standard deviation is $0.49 and that a sample of 32 theaters was randomly selected. Complete parts a through d below.
a. Calculate the standard error of the mean.
b. What is the probability that the sample mean will be less than 10.31?
c. What is the probability that the sample mean will be less than $10.11?
d. What is the probability that the sample mean will be more than $10.26?
(Round everything to four decimal places as needed.)
In: Statistics and Probability
Suppose that the failure rate (failing to detect smoke when smoke is present) for a brand of smoke detector is 1 in 2000. For safety, two of these smoke detector are
installed in a laboratory.
(a) What is the probability that smoke is not detected in the laboratory when smoke
is present in the laboratory?
(b) What is probability that both detectors sound an alarm when smoke is present in
the laboratory?
(c) What is the probability that one of the detectors sounds the alarm and the other
fails to sound the alarm when smoke is present in the laboratory?
In: Statistics and Probability
According to a report from Microsoft, 24% of PCs worldwide are
not adequately protected by antivirus software.19 Suppose 200 PCs
from around the world are selected at random.
a. Find the distribution of the sample proportion of PCs that
are not adequately protected.
b. Find the probability that the sample proportion is less
than 0.20.
c. Find the probability that the sample proportion is more
than 0.29.
d. Find a value v such that the probability the sample
proportion is less than v is 0.01.
In: Statistics and Probability