A psychologist claims that the mean age at which children start walking is 12.5 months. The following data give the age at which 18 randomly selected children started walking.

14 11 17 13 15 13 17 11 18

17 13 17 15 15 16 13 15 14

Test at the 1% level of significance if the mean age at which children start walking is more than 12.5 months.

Suppose there is a simple index of three stocks, stock abc, stock xyz, and stock qrs. stock abc opens on day 1 with 4000 shares at $3.15 per share. stock xyz opens on day 1 with 5000 shares at $4.30 per share. stock qrs opens on day 1 with 6000 shares at $4.60 per share. the price of stock abc on day 8 begins at $3.50. the price of stock xyz on day 8 begins at $3.90. stock qrs opens on day 8 with a price of $4.50 per share. assume that each stock has the same number of shares that it opened with on day 1. what is the rate of change of this simple index over 1 week?

What is the solution of the systems of equations? y=2/3x+3 x=-2

What is the rate of change of a line that passes through (2,-5) and (6,-2)?