Question

The weights of steers in a herd are distributed normally. The standard deviation is 200 lbs and the mean steer weight is 1000 lbs. Find the probability that the weight of a randomly selected steer is between 1160 and 1260 lbs. Round your answer to four decimal places.

Answer 1

Solution :

Given that,

mean = = 1000

standard deviation = = 200

P (1160 < x < 1260 )

P ( 1160 - 1000 / 200 ) < ( x -  / ) < ( 1260- 1000 / 200 )

P ( 160 / 200 < z < 260 / 200)

P ( 0.8 < z < 1.3)

P ( z < 1.3 ) - P ( z < 0.8 )

Using z table

= 0.9032 - 0.7881

= 0.1151

Probability = 0.1151