30 less than 4 times a number is equal to 14

Anyone know these questions? i need ,.

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?

Which of the following values have 3 significant figures? check all that apply. a. 10.1 b. 100.05 c. 120 d. 129