Chapter 5
What mathematical operation is used when "not" ends up in a probability problem?
Subtraction
16.9% of FBI agents are female. In a random sample of 25 FBI agents 3 are female. Identify n, p, and x.
n = 25
p = 0.169
x = 3
IQ scores of adults are normally distributed with a mean of 100 and a standard deviation of 15. What is the probability an adult will have an IQ above 110?
0.252
How large does a sample size need to be ensure that the central limit will apply?
30
Consider a standard deck of cards. What is the probability a randomly selected card has a number on it?
36/52
16.9% of FBI agents are female. What is the probability in a random sample of 25 FBI agents that 3 are female?
0.143
The price of college math text books are normally distributed with a mean of $168 and a standard deviation of $26. What is the probability a college math textbook will cost less than $125?
0.049
9.4% of children between ages 2 to 17 in the U.S. have an ADHD diagnosis. In a sample of 450 children 8% have an ADHD diagnosis.
What is the population proportion?
What is the sample proportion?
population proportion = 0.094
sample proportion 0.08
Consider a spinner that has numbers 1 to 20. What is the probability the spinner will land on a multiple of 5 or an odd number?
12/20
You work for a bank. It is known that 3% of all credit card transactions in your region are fraudulent. You pull a sample of 75 transactions. What is the mean number of fraudulent transactions?
2.25
The price of college math text books are normally distributed with a mean of $168 and a standard deviation of $26. What is the probability a college math textbook will cost between $130 and $150?
0.172
9.4% of children between ages 2 to 17 in the U.S. have an ADHD diagnosis. In a sample of 450 children 8% have an ADHD diagnosis.
What is the standard deviation of the sampling distribution of proportions?
0.014
Box of 12 light bulbs. 9 are good and 3 are defective. What is the probability you randomly choose 2 and they are both good?
72/132
You work for a bank. It is known that 3% of all credit card transactions in your region are fraudulent. You pull a sample of 75 transactions. What is the standard deviation for the number of fraudulent transactions?
1.48
The weights of adult male Labrador Retrievers are normally distributed with a mean of 87 pounds and a standard deviation of 8 pounds. What weight separates the lightest 30% of male Labrador Retrievers?
82.8 pounds
9.4% of children between ages 2 to 17 in the U.S. have an ADHD diagnosis. What is the probability in a sample of 450 children less than 8% have an ADHD diagnosis?
0.159
Randomly select 1 card from a standard deck of cards. What is the probability it has a number on it given that it is a heart?
9/13
You work for a bank. It is known that 3% of all credit card transactions in your region are fraudulent. You pull a sample of 75 transactions. Would it be unusual to find 5 fraudulent transactions? You must explain why!
No
Suppose the time that Americans spend watching TV per day is normally distributed with a mean of 2 hours and standard deviation of 0.75 hours. What time separates the longest 15% of times?
8.78 hours
The average student loan debt for college graduates is $25,050 with a standard deviation is $12,000. What is the probability a sample of 100 college graduates their mean student load debt is greater than $27,000?
0.052