Answer:
92% Confidence Interval = [8.515, 8.605]
Step-by-step explanation:
The number of samples given is 15,this less than 30, hence, we use the t score confidence Interval
= Mean ± t score × Standard deviation/√n
Mean = 8.56 ounces
Standard deviation = 0.09 ounces
n = 15
We find the degrees of freedom = n - 1
= 15 - 1 = 14
Using the T score table
T score for 92% confidence interval with degrees of freedom 14
= 1.8875
Hence:
Confidence Interval =
= 8.56 ± 1.8875 × 0.09/√15
= 8.56 ± 0.0454010035
Confidence Interval
8.56 - 0.0454010035
= 8.5145989965
≈ 8.515
8.56 + 0.0454010035
= 8.6054010035
≈ 8.605
92% Confidence Interval = [8.515, 8.605]
Answer:
7560
Step-by-step explanation:
I used google calculator
It is 180 because it rotates
The answer can be readily calculated using a single variable, x:
Let x = the amount being invested at an annual rate of 10%
Let (8000 - x) = the amount being invested at an annual rate of 12%
The problem is then stated as:
(x * 0.10) + ((8000 - x) * 0.12) = 900
0.10(x) + ((8000 * 0.12) - 0.12(x)) = 900
0.10(x) + 960 - 0.12(x) = 900
0.10(x) - 0.12(x) = 900 - 960
-0.02(x) = -60
-0.02(x) * -100/2 = -60 * -100/2
x = 6000 / 2
x = 3000
Thus, $3,000 is invested at 10% = $300 annually; and $8,000 - $3,000 = $5,000 invested at 12% = $600 annually, which sum to $900 annual investment.