Find the diameter of a circle with an area of 226.98

Weekly wages at a certain factory are normally distributed with a mean of $400 and a standard deviation of $50. find the probability that a worker selected at random makes between $450 and $500

Tom can paint the fence in 12 hours, but if he works together with a friend they can finish the job in 8 hours. how long would it take for his friend to paint this fence alone?

Me its important ! marge runs an ice cream parlor. her speciality is triple chocolate sundaes.she can prepare 1 sundae every 2 minutes, and she earns $1.20 for each sundae she makes . if she just makes sundaes for a single shift of at most 4 hours and at least 2 hours , which function relates her earnings to the number of minutes she works?