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.

Factors like the unemployment rate,the stock market,global trade,economic policy,and the economic situation of other countries have no influence on the financial status of individuals. true or false

Areal estate agent is considering changing her cell phone plan. there are three plans to choose from, all of which involve a monthly service charge of $20. plan a has a cost of $.42 a minute for daytime calls and $.17 a minute for evening calls. plan b has a charge of $.52 a minute for daytime calls and $.15 a minute for evening calls. plan c has a flat rate of $80 with 275 minutes of calls allowed per month and a charge of $.38 per minute beyond that, day or evening.a. determine the total charge under each plan for this case: 150 minutes of day calls and 70 minutes of evening calls in a month. (do not round intermediate calculations. round your answer to 2 decimal places. omit the "$" sign in your response.)c. if the agent will use the service for daytime calls, over what range of call minutes will each plan be optimal? (round each answer to the nearest whole number.include the indifference point itself in each answer.)d. suppose that the agent expects both daytime and evening calls. at what point (i.e., percentage of total call minutes used for daytime calls) would she be indifferent between plans a and b?

Your dormitory, griffingate, has appointed you central banker of its economy, which deals in the currency of wizcoins. assume that the velocity of wizcoins in griffingate is constant at 10,000 transactions per year. right now, real gdp is 1,000 wizcoins, and there are 2,000 wizcoins in existence.