I guess you are asking to find the sum of the first 8 terms. If so, then:
Sum = a₁(1-rⁿ)/(1-r), where a₁ is the 1st term, r=common ratio and n=number of terms:
the 1st term a₁ =3
common ratio r = - 2 (since -6/3 = - 2, and 12/-6 = - 2, etc.)
Sum = 3[(1- (-2)⁸]/(1-2) = 3(1- 256)/(1/2)
Sum = -1530
Answer:
x less than 1
Step-by-step explanation:
Answer:
10+5x
Step-by-step explanation: First 3x becomes a neggative thus saying there is a minus infront of it then combine the like therms with 8x making it 5x. Once you do that take 7 and add it to 3. Therefore the answer is 5x+10.
Answer:
Step-by-step explanation:
Sample standard deviation is found by steps below.
<u>Find the mean:</u>
- μ = (9 + 15 + 13 + 9 + 15)/5 = 12.2
<u>Find deviations from the mean and their squares:</u>
- 9 - 12.2 = - 3.2 ⇒ (-3.2)² = 10.24
- 15 - 12.2 = 2.8 ⇒ 2.8² = 7.84
- 13 - 12.2 = 0.8 ⇒ 0.8² = 0.64
- 9 - 12.2 = - 3.2 ⇒ (-3.2)² = 10.24
- 15 - 12.2 = 2.8 ⇒ 2.8² = 7.84
<u>Sum the squares:</u>
- 10.24*2 + 7.84*2 + 0.64 = 36.8
<u>Divide by N - 1 (N - number of samples):</u>
<u>Square root is the sample standard deviation:</u>
