
Given:
population mean, μ =135
population standard deviation, σ = 15
sample size, n = 19
Assume a large population, say > 100,
we can reasonably assume a normal distribution, and a relatively small sample.
The use of the generally simpler formula is justified.
Estimate of sample mean

Estimate of sample standard deviation


to 5 decimal places.
Thus, using the normal probability table,





Therefore
The probability that the mean weight is between 125 and 130 lbs
P(125<X<130)=0.0731166-0.0018308
=
0.0712858
B. 45 items x $2 = 90$. 90 + the 25 from the beginning = 115
Eddie and Gavin are 40 meters apart.
The last one + has an times eight