Terms & Conditions
How Certain are you?
Table Read
Chances Are...
Act Normal
100
The result of a single probability experiment.
What is an outcome?
100
The probability that an event will happen is P(E) = 30/41 . Find the probability that the event will not happen.
What is P(E') = 11/41 ?
100
A company is conducting a survey to determine how prepared people are for a long-term power outage, natural disaster, or terrorist attack. The frequency distribution below shows the results.
Find the probability that the next person surveyed is very prepared.
What is P(Very Prepared) = 0.125?
100
Two events are mutually exclusive. Find the probability P(A and B).
What is P (A and B)=0?
100
For the standard normal curve, find the z-score that corresponds to the 69th percentile.
What is z = 0.497?
200
A set of one or more possible outcomes.
What is an event?
200
Find the mean, variance, and standard deviation of the binomial distribution with the given values of n and p.
n=129, p=0.21
What is mu = 27.1, sigma ^2=21.4, sigma=4.6 ?
200
The number of dogs per household in a small town.
Find the mean, variance, and standard deviation of the probability distribution.
What is mu=0.6, sigma^2=0.9, and sigma=1 ?
200
Two cards are selected from a standard deck of 52 playing cards. The first card is not replaced before the second card is selected. Find the probability of selecting a heart and then selecting a diamond.
What is P(H and D) = 0.064?
200
In a survey of male infants from 3 to 5 months of age, head circumference was found to be normally distributed, with a mean of 42.9 centimeters and a standard deviation of 1.5 centimeters.
Find the probability that a randomly selected infant from the survey had a head circumference of less than 41 centimeters.
What is P (x<41) = 0.1026 ?
300
When the occurrence of one event does not affect the probability of the occurrence of the other event.
What are independent events?
300
In gambling, the chances of winning are often written in terms of odds rather than probabilities.
The odds of winning is the ratio of the number of successful outcomes to the number of unsuccessful outcomes.
The odds of losing is the ratio of the number of unsuccessful outcomes to the number of successful outcomes.
The odds of winning an event occurring are 3:4. Find the probability of winning.
What is P(Win) = 0.429
300
The probability distribution of number of televisions per household in a small town.
Find the probability of randomly selecting a household that has two or more televisions.
What is P(2 or more) = 0.86?
300
Of the cartons produced by a company, 7% have a puncture, 5% have a smashed corner, and 1.3% have both a puncture and a smashed corner. Find the probability that a randomly selected carton has a puncture or a smashed corner.
What is P(P or SC) = 0.107?
300
In a recent study involving 54 women, the mean body temperature of the women was found to be 97.2°F, with a standard deviation of 0.83. Random samples of size 36 are drawn from this population, and the mean of each sample is determined. Find the mean and standard error of the mean. (Adapted from PLOS One)
What is mu_(barx) = 97.2, sigma_barx = 0.138 ?
400
The ________ of a discrete random variable is equal to the mean of the random variable.
What is the expected value?
400
Fifty-five percent of consumers prefer to purchase electronics online. You randomly select 8 consumers. Find the probability that the number of consumers who prefer to purchase electronics online is exactly five.
What is P(5)=0.257?
400
The accompanying table shows the numbers of male and female students in a certain region who received bachelor's degrees in a certain field in a recent year. A student is selected at random.
Find the probability of that student is not female or received a degree outside of the field
What is P(M or Outside) = 0.930?
400
21% of college students say they use credit cards because of the rewards program. You randomly select 10 college students and ask each to name the reason he or she uses credit cards. Find the probability that the number of college students who say they use credit cards because of the rewards program is between two and five inclusive.
What is P(2<=x<=5)=0.645 ?
400
The annual salaries for entry-level marketing analysts in Pennsylvania are normally distributed, with a mean of about $72,000 and a standard deviation of about $25,000. Random samples of size 38 are drawn from this population, and the mean of each sample is determined. Find the mean and standard error of the mean.
What is mu_barx = $72,000 , sigma_barx = $4055.54 ?