I NEED HELP ASAP PLZ

You are at a restaurant and owe $38 for your meal. you want to leave a 20% tip. how much will your tip be?

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?

Adriana had a garden where he measured the height of a corn plant. what. on the first day,it was 145 cm tall.after 2 weeks is grew by 23 cm.what is the height of the corn plant