Question

11. The SAT scores are known to be normally distributed with an average of 1500 and standard deviation of 300. Lily is a randomly selected test taker, and nothing is known about her SAT aptitude. The probability Lily scores at least 1630 on her SAT test is nearly?

Answer 1

Solution :

Given that ,

mean = = 1500

standard deviation = = 300

P(x 1630) = 1 - P(x   1630)

= 1 - P[(x - ) / (1630 - 1500) / 300]

= 1 -  P(z 0.43)   

= 1 - 0.6664

= 0.3336

Probability = 0.3336