A30-gram sample of bacteria has some unknown disease that is killing the bacteria. the amount of bacteria is measured each day and the results are shown in the table. number of days (d) 0 1 2 3 4 5 6 amount of bacteria in grams (a) 30 28.5 27.075 25.72 24.44 23.21 22.05 what is the decay factor 9f the data

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?