Given:
First term of an arithmetic sequence is 2.
Sum of first 15 terms = 292.5
To find:
The common difference.
Solution:
We have,
First term: 
Sum of first 15 terms: 
The formula of sum of first n terms of an AP is
![S_n=\dfrac{n}{2}[2a+(n-1)d]](https://tex.z-dn.net/?f=S_n%3D%5Cdfrac%7Bn%7D%7B2%7D%5B2a%2B%28n-1%29d%5D)
Where, a is first term and d is common difference.
Putting
, n=15 and a=2 in the above formula, we get
![292.5=\dfrac{15}{2}[2(2)+(15-1)d]](https://tex.z-dn.net/?f=292.5%3D%5Cdfrac%7B15%7D%7B2%7D%5B2%282%29%2B%2815-1%29d%5D)
![292.5=\dfrac{15}{2}[4+14d]](https://tex.z-dn.net/?f=292.5%3D%5Cdfrac%7B15%7D%7B2%7D%5B4%2B14d%5D)
![292.5=15[2+7d]](https://tex.z-dn.net/?f=292.5%3D15%5B2%2B7d%5D)
Divide both sides by 15.




Dividing both sides by 7, we get


Therefore, the common difference is 2.5.
Answer is in a photo. I couldn't attach it here, but I uploaded it to a file hosting. link below! Good Luck!
bit.
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Answer:
A. 0.0049
B. Yes
Step-by-step explanation:
Sample proportion = 0.64
N = 1000
Population proportion = 0.60
We solve for standard deviation
= √p(1-p)/n
= √0.60(1-0.60)/1000
= √0.60x0.40/1000
= √0.00024
= 0.0155
A.
The probability of sample >=0.64
Z>=0.64-0.60/0.0155
Z >= 0.04/0.0155
So z >= 2.5806
Using excel this equal to 0.0049
0.0049 is probability of sample proportion being 0.64 at least.
B.
This answer in a shows that than 60% of households in the united states income class purchased life insurance last year.
C I think because it shows the months and the total
Answer:
62.8 inches
Step-by-step explanation:
c = πd
c = 3.14 * 20
c = 62.8 inches