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
Answer:
8
Step-by-step explanation:
that;'s what i put the first time
Alright, so first of all, you need to find the area of the circle that is part of the cone-shaped area so you can remove it. You need the formula:
where c = angle. Now plug in the answers, and you get:

.
This would then equal to
.
now, essentially, the shape of this ENTIRE area is of 2 right triangles. Divide 120 by 2, you get 60 degrees. You have 2 60/30/90 triangles (shown in the bottom)
Now, what you need to do is to find the area of the entire thing by using the formula to calculate the right triangle area (A = (1/2)bh). You have
b, which is
6. To find the h, you use
tan(60) = x/6, which gives you

.
The area of one right triangle of this size would be =

Because 2 right triangles, multiply the area by 2 and get:

Now, remember the area of that circle in that total area? subtract it from the total area (

) by 12pi and you get 24.65.
The final answer is 24.65
Well 5=5
and 37/40
hmm, try to get that 40 into an nice number that is multiplule of 10
if we divide top and bottom by 4 that would work

9.25/10=92.5=100=925/1000=925 thousandths=0.925
so the decimal would be 5.925