Probability
Normal and Z
Empirical Rule
Confidence Intevals and Hypothesis Tests
Potpourri
100
If you toss a coin 50 times, what is the probability that you toss heads on the 32nd toss?
What is 50%
100
In a normal curve, the highest point is above __
What is the mean (mu)
100
What percentage of the area under a normal curve is to the right of the mean (mu)?
What is 50%
100
What is the symbol for the alternate hypothesis?
What is H sub 1
100
If a sample has 23 elements, how many degrees of freedom does it have?
What is 22
200
The probability that merchandise stolen from a store will be recovered is 15%. Suppose a random sample is taken from 8 stores from which merchandise has been taken. The mean of the distribution is __
What is 1.2
200
A normal curve is the graph of a normal __
What is distribution
200
What percentage of the area under a normal curve is between -1 standard deviation (-sigma) and +1 standard deviation (+sigma)?
What is 68%
200
Use the Students t-distribution table to find t sub c for a 95% confidence level when the sample size is 18
What is 2.110
200
If mu = 100 and sigma = 48, for a sample of size 81, what is mu sub x-bar?
What is 100
300
The probability that merchandise stolen from a store will be recovered is 15%. Suppose a random sample is taken from 8 stores from which merchandise has been taken. The standard deviation of the probability distribution is ?
What is 1.01
300
A normal curve never crosses or touches this.
What is the x-axis
300
What percent of the area under a normal curve is between mean - 2 standard deviations (mu - 2sigma) and mean + 2 standard deviations (mu + 2sigma)?
What is 95%
300
Find a 95% confidence interval for the mean serum level of vitamin E in similar persons if there were 99 patients in the sample, and those 99 patients had a mean vitamin E level of 10.5 mg/L with a standard deviation of 3.2 mg/L.
What is (9.87, 11.13)
300
If mu = 100 and sigma = 48, for a sample of size n = 81, what is sigma sub x-bar?
What is 5.33
400
Let X be the outcome of rolling a fair six-sided die. What is P(2 < X < 5)
What is 2/6 or 1/3
400
Z-scores measure the number of these that an original value is from the mean.
What is standard deviations
400
What percentage of the area under a normal curve lies to the right of mean + 3 standard deviations (mu + 3sigma)?
What is .15%
400
For the following data set, use a 5% level of significance to test the claim that the population average heart rate of a lion is different (either way) from 40 beats per minute. What would you do with the null hypothesis?
What is fail to reject it.
400
Of those people who lose weight on a diet, 90% gain all of the weight back. In a random sample of 12 dieters who have lost weight, what is the probability that at least 9 gain the wight back?
What is 98%
500
For a given probability distribution, the P(x=0)=0.2, P(x=1)=0.6, and P(x=2)=0.2. What is the mean of x?
What is 1
500
In a standard normal distribution, what are the values for the mean (mu) and the standard deviation (sigma)?
What is mu = 0, sigma = 1
500
Assuming the heights of college women are normally distributed, with mean 65 inches and standard deviation 2.5 inches, what percentage of women are between 62.5 and 67.5 inches?
What is 68%
500
What makes a data set not statistically significant.
What is failing to reject the null hypothesis
500
Of those people who lose weight on a diet, 90% gain all the weight back. In a random sample of 12 dieters who have lost weight, what is the probability that no more than 6 gain the weight back?
What is about 0%.
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