SOLUTION: the mean baggage weight for each adult is 60kg. To test his belief, he draws a random sample of 50 adult passengers and weights their baggage. Hends the sample mean to be 57:1kg. I

Algebra ->  Probability-and-statistics -> SOLUTION: the mean baggage weight for each adult is 60kg. To test his belief, he draws a random sample of 50 adult passengers and weights their baggage. Hends the sample mean to be 57:1kg. I      Log On


   



Question 1124494: the mean baggage weight for each adult is 60kg. To test his belief, he draws a random sample of 50 adult passengers and weights their baggage. Hends the sample mean to be 57:1kg. If he knows that the population standard deviation is 10kg, the probability that the average baggage weight is at most 57:1 is?
Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
since we know the standard deviation of the population and the sample size is > 30, we can use the Normal distribution
:
Standard Error = 10 / square root(50) = 1.4142
:
z-score = (57.1 - 60) / 1.4142 = -2.05
:
Probability (X < 57.1) associated with a z-score of -2.05 = 0.0202
: