Answer:
y==$281+$166=$447
in 11 weeks she pay $ 447
in 1 weeks she pay $447/11=40.6$
she paid off in 3+8=11 weeks
I am not sure
The sample std. dev. will be (14 inches) / sqrt(49), or (14 inches) / 7, or 2 inches.
Find the z score for 93.8 inches:
93.8 inches - 91.0 inches 2.8 inches
z = ------------------------------------- = ----------------- = 1.4
2 inches 2 inches
Now find the area under the standard normal curve to the left of z = +1.4.
My calculator returns the following:
normalcdf(-100,1.4) = 0.919. This is the probability that the mean annual precipitation during those 49 years will be less than 93.8 inches.
