# SOLUTION: The monthly utility bills are normally distributed with a mean value of \$160 and a standard deviation of \$25. (a) Find the probability of having a utility bill between 120 and 180

Algebra ->  Algebra  -> Probability-and-statistics -> SOLUTION: The monthly utility bills are normally distributed with a mean value of \$160 and a standard deviation of \$25. (a) Find the probability of having a utility bill between 120 and 180      Log On

 Ad: Algebra Solved!™: algebra software solves algebra homework problems with step-by-step help! Ad: Algebrator™ solves your algebra problems and provides step-by-step explanations!

 Algebra: Probability and statistics Solvers Lessons Answers archive Quiz In Depth

 Question 600420: The monthly utility bills are normally distributed with a mean value of \$160 and a standard deviation of \$25. (a) Find the probability of having a utility bill between 120 and 180. (b) Find the probability of having a utility bill less than \$120. (c) Find the probability of having a utility bill more than \$210. Answer by sniper619(1)   (Show Source): You can put this solution on YOUR website!a) P(120< x <180) = P( (120-160/25)< z < (180-160/25) ) = P( -1.6 < z < 0.8) = P(z < 0.8) - P(z > 1.6) = 0.7881 - (1-0.9452) = 0.7881 - 0.0548 = 0.7333 b) P( x<120 ) = P( z < (120-160/25) ) = P( z < -1.6 ) = 1 - 0.9452 = 0.0548 c) P( x>210 ) = P( z > (210-160/25) ) = P( z > 2 ) = 1 - 0.9772 = 0.0228 Note: Used a Normal Distribution Function Table.