Essentials of Statistics for the Behavioral Sciences
8th Edition
ISBN: 9781133956570
Author: Frederick J Gravetter, Larry B. Wallnau
Publisher: Cengage Learning
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Chapter 7, Problem 21P
The average age for licensed drivers in the county is μ = 40.3 years with a standard deviation of σ = 13.2 years.
- a. A researcher obtained a random sample of n = 16 parking tickets and computed an average age of M = 38.9 years for the drivers. Compute the z-score for the sample mean and find the
probability of obtaining an average age this young or younger for a random sample of licensed drivers. Is it reasonable to conclude that this set of n = 16 people is a representative sample of licensed drivers? - b. The same researcher obtained a random sample of n = 36 speeding tickets and computed an average age of M = 36.2 years for the drivers. Compute the z-score for the sample mean and find the probability of obtaining an average age this young or younger for a random sample of licensed drivers. Is it reasonable to conclude that this set of n = 36 people is a representative sample of licensed drivers?
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Chapter 7 Solutions
Essentials of Statistics for the Behavioral Sciences
Ch. 7.2 - A population has a mean of = 65 and a standard...Ch. 7.2 - Describe the relationship between the sample size...Ch. 7.2 - For a population with of = 40 and a standard...Ch. 7.3 - A sample is selected from a population with a mean...Ch. 7.3 - What is the probability of obtaining a sample mean...Ch. 7.3 - What are the boundaries for the middle 50% of all...Ch. 7.4 - If a sample is selected from a population with a...Ch. 7.4 - Can the value of the standard error ever be larger...Ch. 7.4 - Prob. 3LCCh. 7.4 - Prob. 4LC
Ch. 7.5 - A population forms a normal distribution with a...Ch. 7.5 - A population forms a normal shaped distribution...Ch. 7.5 - The SAT scores for the entering freshman class at...Ch. 7.5 - Prob. 4LCCh. 7 - Describe the distribution of sample means (shape,...Ch. 7 - A sample is selected from a population with a mean...Ch. 7 - The distribution of sample means is not always a...Ch. 7 - A population has a standard deviation of = 24. a....Ch. 7 - For a population with a mean of = 70 and a...Ch. 7 - For a population with a standard deviation of =...Ch. 7 - For a population with = 12, how large a sample is...Ch. 7 - For a sample of n = 25 scores, what is the value...Ch. 7 - For a population with a mean of = 80 and a...Ch. 7 - A sample of n = 4 scores has a mean of M = 75....Ch. 7 - A normal distribution has a mean of = 60 and a...Ch. 7 - A random sample is obtained from a normal...Ch. 7 - The population of IQ scores forms a normal...Ch. 7 - The scores on a standardized mathematics test for...Ch. 7 - A normal distribution has a mean of = 54 and...Ch. 7 - A population of scores forms a normal distribution...Ch. 7 - For random samples of size n = 25 selected from a...Ch. 7 - The distribution ages for students at the state...Ch. 7 - At the end of the spring semester, the Dean of...Ch. 7 - Jumbo shrimp are those that require 10 to 15...Ch. 7 - The average age for licensed drivers in the county...Ch. 7 - Callahan (2009) conducted a study to evaluate the...Ch. 7 - Xu and Garcia (2008) conducted a research study...
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