Answer:
is proved for the sum of pth, qth and rth terms of an arithmetic progression are a, b,and c respectively.
Step-by-step explanation:
Given that the sum of pth, qth and rth terms of an arithmetic progression are a, b and c respectively.
First term of given arithmetic progression is A
and common difference is D
ie.,
and common difference=D
The nth term can be written as

pth term of given arithmetic progression is a

qth term of given arithmetic progression is b
and
rth term of given arithmetic progression is c

We have to prove that

Now to prove LHS=RHS
Now take LHS




![=\frac{[Aq+pqD-Dq-Ar-prD+rD]\times qr+[Ar+rqD-Dr-Ap-pqD+pD]\times pr+[Ap+prD-Dp-Aq-qrD+qD]\times pq}{pqr}](https://tex.z-dn.net/?f=%3D%5Cfrac%7B%5BAq%2BpqD-Dq-Ar-prD%2BrD%5D%5Ctimes%20qr%2B%5BAr%2BrqD-Dr-Ap-pqD%2BpD%5D%5Ctimes%20pr%2B%5BAp%2BprD-Dp-Aq-qrD%2BqD%5D%5Ctimes%20pq%7D%7Bpqr%7D)




ie., 
Therefore
ie.,
Hence proved
Answer:
0.1507 or 15.07%.
Step-by-step explanation:
We have been given that the manufacturing of a ball bearing is normally distributed with a mean diameter of 22 millimeters and a standard deviation of .016 millimeters. To be acceptable the diameter needs to be between 21.97 and 22.03 millimeters.
First of all, we will find z-scores for data points using z-score formula.
, where,
z = z-score,
x = Sample score,
= Mean,
= Standard deviation.



Let us find z-score of data point 22.03.



Using probability formula
, we will get:

Therefore, the probability that a randomly selected ball bearing will be acceptable is 0.1507 or 15.07%.
Answer:
A is 2 out of 6
Step-by-step explanation:
Probability of him pulling the one with parallel sides is 2/6 because there are only two out of 6 with parallel lines
Answer: a + 4
explanation: sum means what comes from two numbers being added. so you just need to add a and 4
Answer:
11 of 20p, 22 of 10p and 33 of 5p
Step-by-step explanation:
Eva has 20p, 10p and 5p coins, total of £6.05 = 605p
Let 20p=x, 10p=y, 5p=z
<u>Then</u>:
- 20x + 10y + 5z = 605
- y : x = 2 : 1 ⇒ x= y/2
- y : z = 2 : 3 ⇒ z= 3y/2
<u>Rewriting the first equation considering next two:</u>
- 10y + 10y + 7.5y = 605
- 27.5y = 605
- y= 605/27.5
- y= 22
- x= y/2 = 22/2 = 11
- z = 3y/2 = 3*11 = 33
<u>Answer:</u> 11 of 20p coins, 22 of 10p coins and 33 of 5p coins