Answer:
0.26599
Step-by-step explanation:
When given a random number of samples, we solve using this z score formula
z = (x-μ)/σ/√n
where x is the raw score = 268
μ is the population mean = 266
σ is the population standard deviation = 16
n = 25
For x > 268
z = 268 - 266/16/√25
z= 2/16/5
z = 0.625
Probability value from Z-Table:
P(x<268) = 0.73401
P(x>268) = 1 - P(x<268)
P(x>268) = 1 - 0.73401
P(x>268) = 0.26599
The probability that the average pregnancy length of the women in the study is more than 268 days is 0.26599