Question

The SAT scores for The amount of annual snowfall in certain mountain ranges is normally distributed with a mean of 70 inches and a standard deviation of 10 inches what is the probability that the annual snowfall for one randomly picked year will be below 73.3 inches. round your answer to 3 decimal who are normally distributed with a mean of 1035 and a standard deviation of 201 what is the probability that a sample of 50 students will have the average score between 1050 and 1065 round your answer to three decimal places

Answer 1

solution

given that

P(X<73.3 ) = P[(X- ) / < (73.3-70) /10 ]

= P(z <0.33 )

Using z table

=0.6293

probability=0.629

(B)

n = 50

= 1035

=  / n= 201/ 50 =28.4257

P(1050<     <1065 ) = P[(1050-1035) / 28.4257< ( - ) /   < (1065-1035) / 28.4257)]

= P( 0.53< Z <1.06 )

= P(Z <1.06 ) - P(Z <0.53 )

Using z table

=0.8554-0.7019

=0.1535

probability= 0.1535