Question

(d) If an order comes in for 10,000 steel? rods, how many rods should the plant manager expect to manufacture if the order states that all rods must be between 29.9 cm and 30.1 ?cm?

Mean = 30

Standard Deviation = 0.07

nvm got it = 11809

Answer 1

Solution :

Given that ,

mean = = 30

standard deviation = = 0.07

n = 10000

P(29.9 < x < 30.1 ) = P[(29.9 - 30 )/ 0.07) < (x - ) /  < (30.1 - 30) / 0.07) ]

= P( -1.43 < z < 1.43)

= P(z < 1.43 ) - P(z < -1.43 )

Using z table,

= 0.9236 - 0.0764

= 0.8472

0.8472 * 10000 = 8472 rods.