"What is the difference between a ratio and its related rate and unit rate?"

Math i have no idea how to do a and b

The slope of the line whose equation is 3y = 2x - 3 is 2 2/3 3/2

Arandom sample of 45 observations results in a sample mean of 68. the population standard deviation is known to be 23 a. compute the margin of error at a 959% confidence interval. b. compute the 95% confidence interval for the population mean c. compute the 90% confidence interval for the population mean. d. compute the 75% confidence interval for the population mean