What is the second part of the second step to prove that S = 1+2+3+...+n = n(n+1)\2?

a. Assume that Sy is valid for n=k.

B. Verify that S, is valid for n=1.

C. Show that is valid for n=k.

D. Prove that s, is valid for n=k+ 1.

What is the slope of the line shown below?

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?

Two rectangular prisms have the same volume. the area of the base of the blue prism is 418 4 1 8 square units. the area of the base of the red prism is one-half that of the blue prism. which statement is true?