Answer:
385
Step-by-step explanation:
Given that :
Mean, m = 500
Standard deviation, s = 100
Zcritical at 95% = 1.96
Confidence interval, C2 - C1 ; 510 - 490
Using the relation :
n = (2 * Zcritical * s) / (C2 - C1)
n = sample size
n = [(2 * 1.96 * 100) / (510 - 490)]^2
n = (392 / 20)^2
n = 19.6²
n = 384.16
n = 385
Answer:
1/5
Step-by-step explanation:
2/5 + 3/5
(2+ 3)/5
2/5 + (2 + 3)/5 = (4 + 3)/5
(4+ 3)/5 = 7/5
4+ 3 = 7
4 = 4
c = 1/5
Area = length x width
So, 36/3 = 12
Width is 12
If these are terms of a geometric sequence, they have a common ratio. That is, ...
... (k -1)/(2(1 -k)) = (k +8)/(k -1)
... (k -1)² = 2(1 -k)(k +8) . . . . . multiply by the product of the denominators.
... k² -2k +1 = -2k² -14k +16 . . . eliminate parentheses
... 3k² +12k -15 = 0 . . . . . . . . put in standard form (subtract the right side)
... 3(k +5)(k -1) = 0 . . . . . . . . . factor
Possible values of k are ... -5, +1. The solution k=1 is extraneous, as it makes the first two terms 0 and the third term 8. (It doesn't work.)
The value of k is -5.
_____
The three terms are 12, -6, 3. The common ratio is -1/2.
