Write an expression to represent each statement. a number decreased by 5

Anormally distributed data set has a mean of 176.3 and a standard deviation of 4.2. what is the approximate z-score for the data value of 167.9? 2.00 −2.00 8.4 −8.4

Why is x= 4 a solution to the proportion 14/x 56/1 6

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?