Umm hey kid what is the problem,how can I help you
Answer: (29.4, 32.6)
Step-by-step explanation:
From the question, we know that
Sample size (n) = 27
Sample mean (x) = $31
Sample standard deviation (s) = $3
We are to construct a 99% confidence interval interval for average amount spent on gift.
The formulae for constructing a 99% confidence interval for population mean is given as
u = x + tα/2 × s/√n...... For upper limit
u = x - tα/2 × s/√n...... For lower limit
tα/2 is the critical value for a 2 tailed test. This value of gotten from a t distribution table by checking the degree of freedom ( 27 - 1 = 26) against the level of significance ( 100% - 99% = 1%).
Hence tα/2 = 2.779
Let us substitute our parameters and solve
For lower limit
u = 31 - 2.779 × 3/√27
u = 31 - 2.779 ( 0.5773)
u = 31 - 1.6045
u = 29.4
For upper limit
u = 31 + 2.779 × 3/√27
u = 31 + 2.779 ( 0.5773)
u = 31 + 1.6045
u = 32.6
Hence the 99% confidence interval for population mean is given as 29.4, 32.6
To solve for the area of a triangle you use the formula A=b*h/2. The base for this triangle is 4 and the height is 8. Take 4*8 which is 32 and divide that answer in half to get 16 which is your answer.
We can use these variables:
A = number of ounces for solution A
B = Number of ounces for solution B
A + B = 20
Now, we can use decimal conversions.
0.65A + 0.80B = 0.70(120)
Next step: We substitute A into 120 - B to show their relationship.
0.65(120 - B) + 0.80B = 84
Now onto the next equation:
78 - 0.65B + 0.80B = 84
0.80 - 0.65 = 0.15, so…
0.15B = 84 - 78
0.15B = 6
B = 6 divided by 0.15
B = 40 ounces
To find A, we can simply plug B into the starting equation.
A = 120 - 40
A = 60 ounces
Your final answer: The scientist should use 60 ounces of solution A and she should use 40 ounces of solution B. Yeah
