Stats Help for College-level Students

True or false question about the area under a normal distribution curve.

True or false: The probability is exactly 0.5 that the total area under the standard normal curve is 1.

Normal Distribution and Others

VISA reported with 95% confidence that 19% of those surveyed used checks to pay for purchases. If 1478 people participated in the survey, what was the percentage of error?

Working with Chi square and significance levels.

What is the value for Chi square left for a 90% confidence interval when n = 16?

Working with probability and normal distribution.

True or false: There is a probability a that a z score will have a value between -za/2 and za/2.

True or false question about a standard normal distribution curve.

True of false: Correct to at least 6 decimal places, the area under a standard normal curve between z = -7 and z = -6 is 0.

True or false question about normal distribution, standard deviation and mean.

True or false: When the variable is normally distributed, the sample size is less than 30, and the population standard deviation is known, then the t distribution must be used to find confidence intervals for the mean.

Working with normal distribution and probability.

The average hourly wage of workers in a fast food restaurant is $5.85 with a standard deviation of $0.35. Assume that the distribution is normal. If a worker at this fast food restaurant is selected at random, what is the probability that the worker earns more than $6.25 an hour?

Normal Distribution and Others

31. In a production run of 40 of a particular model of radiation detector, there are four which have defective circuits. If a sample of three of these is chosen without replacement, what is the probability that all three will be defective?

True or false question about normal distribution and percentiles.

True or false: It is not possible for the score in a distribution, not necessarily normal, which ranks as the 90th percentile to also be the mode for the distribution.

Statistics: Multiple Choice Questions

Multiple choice statistics questions on Chebyshev's theorem, standard deviation, coefficient of variation, relative dispersion, Pearson's coefficient of skewness, and sample variance. See attached file for full problem description.