Math Is Fun Forum

Let's say for example,
Matrices A1;A2;A3 with dimensions:

A1 = 5x10
A2 = 10x3
A3 = 3x10

Would M[2,3] be equal to (10*3*10) or (10*3)?

Hi, I am stuck on the last step. What am I supposed to do now?

Problem: Let T(n)=3T(n-1)+2, T(1)=2. Prove by induction that T(n)=3^(n-1)

Here is what I have so far:

Show base case k=1: T(1) = 3^1 - 1 = 2

Show for k=n-1: T(n-1) = (3^((n-1)-1)) -1

Show for k=n :
3((3^(n-2)) - 1) + 2

Hi, the problem is:
Find Z.025; that is find Z which cuts off a right-hand tail probability 0.025

The "Z.025" part looks like this:
http://i.imgur.com/CnZdc.png  (didn't know how to type it out)

The answer is .70, but I don't know how it was calculated.

Hi, I am a bit confused about this problem.

For each of the following random variables, tell whether it would naturally represent a finite, discrete or continuous random variable. Explain your reasoning.

a) X is the number of customers who walk into a shop between noon and 1PM on some particular day.
b) X is the amount of orange juice in a randomly chosen 8-ounce carton of juice.
c) X is the amount of times you play the lottery until you win? We'll assume that once you win you stop playing.
d) X is the number of women in a randomly chosen sample of 500 New York City residents.

For the answers I got:

a) Finite because the amount of people between the noon and 1PM are countable.
b) Continuous because the amount of juice is uncountable.
c) Continuous because you don't know when you will win.
d) Discrete because it is taking a number of people from a set amount.