Stats Help for College-level Students

Elementary Statistics: Hypothesis Testing

See attachment. Elementary statistics. Please provide me solutions with formulas and calculations. Its required that you provide step by step solutions to that I can compare my answers and fill in the attached answer sheet. Hypothesis testing on charitable donations, cigarette smoking, and small businesses.

Normal distribution and significance levels

True or false: The value for a chi square right for a 95% confidence interval when n = 16 is 27.488.

Significance levels, mean, z score, and standard deviation

True or false: Fred wants to calculate the 98% confidence interval around the mean using the z-distribution. His sample of 64 items has a mean of 35 and a standard deviation of 6. The maximum error of estimate would be 0.218.

Normal distribution and significance levels

True or false: A retailer wants to estimate with 99% confidence the number of people who buy at his store. A previous study showed that 15% of those interviewed had shopped at his store. He wishes to be accurate within 3% of the true proportion. The minimum sample size necessary would be 940.

Normal Distribution

A tornado has blown through a section of Collinsville. The insurance adjuster wants to estimate the average claim to within $500. If the standard deviation is believed to be $1600 and the company wants to be 99% sure of their figures, how large a sample must be taken?

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

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.

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.