Question

Law of Large Numbers: I need help finding Probability

Answer 1

the variance of both curves is the sum of the variances
V_sum=V_walk+V_bus
the standard deviation is thus the square root of the sum of the squares
\(\Huge \sigma_{total}=\sqrt{\sigma_{bus}^2+\sigma_{walk}^2}\)

Answer 2

using the value you obtain from c, you can now calculate the probability, given that the mean is simply the sum of the two means

Answer 3

Oh, my bad, misread

Answer 4

do you remember how to calculate z scores? you are working with a normal distribution here

Answer 5

either use your calculator or a z score table.
note: the formula you're using is wrong, but it gives you the right answer

Answer 6

uhm

Answer 7

the formula is (observation-mean)/(SD)
that actually gives you positive .447.
Let's draw a graph and visualize what we're doing here

Answer 8

yeah

Answer 9

that's what we're looking for