Is this an example of direct variation? f(x)=2xy

Is a positive integer raised to a negative power always positive

Bonnie and bobby are saving money for a vacation. each friend starts with an amount and also saves a specific amount each week. bonnie created a table to show the total she has saved at the end of each week.. weeks 0 1 2 3 4 5 6 7 8 amount saved 12 16 20 24 28 32 36 40 44 bobby came up with the following equation to show the total, y, he has saved at the end of each week, x. y = 12x + 4 compare the rate at which each friend saves money. select the correct answer from the drop-down menu to complete the statement. the rate at which bobby is adding to his savings each week is $ more than the rate at which bonnie is adding to her savings each week.

1. according to the internal revenue service, the mean tax refund for the year 2007 was $2,708. assume the standard deviation is $650 and that the amounts refunded follow a normal probability distribution. a. what percent of the refunds are more than $3,000? b. what percent of the refunds are more than $3,000 but less than $4,000? c. what percent of the refunds are less than $2,000?