Answer:
the probability that a sample of 4 bags will have a mean weight less than 9.8 pounds is 0.05
Step-by-step explanation:
Given the data in the question;
μ_x = 10 pound bags
standard deviation s_x = 0.24 pounds
sample size n = 4
The bag weights are normally distributed so;
p( x' less than 9.8 ) will be;
p( (x'-μ_x' / s_x') < (9.8-μ_x' / s_x') )
we know that;
μ_x' = μ_x = 10
and s_x' = s_x/√n = 0.24/√4
so; we substitute
p( z < ( (9.8 - 10) / (0.24/√4) )
p( z < -0.2 / 0.12 )
p( z < -1.67 )
{ From z-table }
⇒ p( z < -1.67 ) = 0.0475 ≈ 0.05
Therefore, the probability that a sample of 4 bags will have a mean weight less than 9.8 pounds is 0.05
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