If other factors are held constant, what happens to a confidence interval if the sample variance increases?

a. the standard error increases and the width of the interval increases.
b. the range of t scores increases and the width of the interval increases.
c. the standard error decreases and the width of the interval decreases.
d. the range of t scores decreases and the width of the interval decreases.

Consider the market for gasoline. suppose that, in a competitive market without government regulations, the equilibrium price of gasoline is $3.00 per gallon, and employees at gas stations earn $17.50 per hour. complete the following table by indicating whether each of the statements is an example of a price ceiling or a price floor and whether it results in a shortage or a surplus or has no effect on the price and quantity that prevail in the market. statement price control effect the government has instituted a legal minimum price of $3.40 per gallon for gasoline. the government prohibits gas stations from selling gasoline for more than $3.40 per gallon. due to new regulations, gas stations that would like to pay better wages in order to hire more workers are prohibited from paying more than $14.50 per hour.

The usa today reports that the average expenditure on valentine's day is $100.89. do male and female consumers differ in the amounts they spend? the average expenditure in a sample survey of 47 male consumers was $135.67, and the average expenditure in a sample survey of 38 female consumers was $68.64. based on past surveys, the standard deviation for male consumers is assumed to be $34, and the standard deviation for female consumers is assumed to be $17.

You are in the market for a new refrigerator for your company’s lounge, and you have narrowed the search down to two models. the energy efficient model sells for $700 and will save you $45 at the end of each of the next five years in electricity costs. the standard model has features similar to the energy efficient model but provides no future saving in electricity costs. it is priced at only $500. assuming your opportunity cost of funds is 6 percent, which refrigerator should you purchase