Answer:
Step-by-step explanation:
The Pascal triangle is used to determine the coefficients of the terms when we expand the expression.
1
= 1
1 1 
1 2 1 
By extending the triangle, you will get the 9th row, which is your expression, of the coefficients. that is
1 9 36 84 126 126 84 36 9 1
Now, fill in AB in the gaps.
1AB + 9 AB + 36AB + 84AB + 126AB + 126AB +84AB + 36AB + 9AB + 1AB
Next, you need to go from the left to fill out the exponent of A and it will go down from 9 (the exponent of the whole thing) . That is

Next will be the exponent of B. this time, you go from the right and do the same with A. You can go from the left also, but go up from 0 to 9 for the exponent of B

The last step is just to simplify the A^0=1 and B^0 =1 at the first and the last terms.

Hope you can learn the method
Memorize the definition of standard deviation: the sd is the square root of the average of the squared deviations of the mean. Wow. Let's do it.
Step 1. First we need the mean. That's easy. Add them up and divide by the count. Check if you get 16.88/5 = 2.81333.
Step 2. Now we're going to subtract this from each of the values, and square the result. Don't worry about negative signs, the squaring will get rid of those. Example for the first number:
(1 - 2.813)^2 = 3.29
The list of numbers I get is (rounded, in reality round as little as possible):
3.29, 2.60, 1.41, 2.35, 1.66, 6.18
Step 3: Add them all up. I get 17.49.
Step 4: Divide by the count of numbers. 17.49/6 = 2.91
Step 5: Take the square root from this result. SQRT(2.91) = 1.707305
TIP: Use excel to do all these steps, then run the set of numbers through Excel's built-in sd function (called STDEV.P) and see that you get the same result!
Answer:
4.74 hours
Step-by-step explanation:
Given that both person have to place same number of rivets that is
11209
first person take 9 hours to complete the work
hence 1 hour work of 1st person is
of total work
second person takes 10 hours to complete the same work
hence 1 hour work of 2nd person is 
Now if both work together then
1 hour work of both person =
=
thus working together they need
hours = 4.74 hours to complete the whole work which is placing 11209 rivets
Graph b has a correlation closest to -0.95