Question

PLEASE SHOW THE DIAGRAM

8. The mean pulse rate for adults is 72 beats per minute (www.healthepic.com) and let’s suppose that the standard deviation is 10. Find:

a. The probability that a randomly chosen adult has a pulse rate over 78 assuming that the rates are normally distributed.

2. The probability that a random sample of 19 adults will have a mean score over 78.

PLEASE DON'T FORGET THE DIAGRAM

Answer 1

Solution :

Given ,

mean = = 72

standard deviation = = 10

P(x >78 ) = 1 - P(x<78 )

= 1 - P[(x -) / < (78 -72) /10 ]

= 1 - P(z <0.6 )

Using z table

= 1 - 0.7257

= 0.2743

probability= 0.2743

(b)

n = 19

= 72

= / n = 10/ 19 = 2.2942

P( > 78) = 1 - P( <78 )

= 1 - P[( - ) / < (78 -72) / 2.2942 ]

= 1 - P(z <2.62 )

Using z table

= 1 - 0.9956

= 0.0044

probability= 0.0044