Answer: ![(57.41,\ 62.19)](https://tex.z-dn.net/?f=%2857.41%2C%5C%2062.19%29)
Step-by-step explanation:
Given : Sample size : ![n=40](https://tex.z-dn.net/?f=n%3D40)
Sample mean : ![\overline{x}=59.8\text{ seconds}](https://tex.z-dn.net/?f=%5Coverline%7Bx%7D%3D59.8%5Ctext%7B%20seconds%7D)
Standard deviation : ![\sigma =9.2\text{ seconds}](https://tex.z-dn.net/?f=%5Csigma%20%3D9.2%5Ctext%7B%20seconds%7D)
Significance level : ![\alpha=1-0.9=0.1](https://tex.z-dn.net/?f=%5Calpha%3D1-0.9%3D0.1)
Critical value : ![z_{\alpha/2}=1.645](https://tex.z-dn.net/?f=z_%7B%5Calpha%2F2%7D%3D1.645)
Formula to find the confidence interval for population mean :-
![\overline{x}\pm z_{\alpha/2}\dfrac{\sigma}{\sqrt{n}}\\\\=59.8\pm(1.645)\dfrac{9.2}{\sqrt{40}}\\\\\approx59.8\pm2.39\\\\=(59.8-2.39,\ 59.8+2.39)\\\\=(57.41,\ 62.19)](https://tex.z-dn.net/?f=%5Coverline%7Bx%7D%5Cpm%20z_%7B%5Calpha%2F2%7D%5Cdfrac%7B%5Csigma%7D%7B%5Csqrt%7Bn%7D%7D%5C%5C%5C%5C%3D59.8%5Cpm%281.645%29%5Cdfrac%7B9.2%7D%7B%5Csqrt%7B40%7D%7D%5C%5C%5C%5C%5Capprox59.8%5Cpm2.39%5C%5C%5C%5C%3D%2859.8-2.39%2C%5C%2059.8%2B2.39%29%5C%5C%5C%5C%3D%2857.41%2C%5C%2062.19%29)
Hence, a 90% confidence interval estimate of the population mean of all students = ![(57.41,\ 62.19)](https://tex.z-dn.net/?f=%2857.41%2C%5C%2062.19%29)
Answer:
420cm cubed
Step-by-step explanation:
D- 1.65 per hot dog
Take the amount of the bag of chips which is 1.25 and multiply it by 5 because that’s how many people there are and they each bought one bag
1.25 x 5= 6.25
Next you want to subtract that amount from the total so we can just have the amount of money spent on hot dogs
22.27-6.25=16.50
Then you want to divide 16.50 by 5 because they all bought the same amount of hot dogs and this will get us to the amount of to hot dogs
16.50/5=3.30
Finally you want to divide 3.30 by 2 which will get us the price for 1 hot dog
3.30/2=1.65
There you go!!
Answer:
a) Find the common ratio of this sequence.
Answer: -0.82
b) Find the sum to infinity of this sequence.
Answer: 2.2
Step-by-step explanation:
nth term in geometric series is given by ![4\ th \ term = ar^n-1\\-2.196 = 4r^{4-1} \\-2.196/4 = r^{3} \\r = \sqrt[3]{0.549} \\r = 0.82](https://tex.z-dn.net/?f=4%5C%20th%20%5C%20term%20%3D%20ar%5En-1%5C%5C-2.196%20%3D%204r%5E%7B4-1%7D%20%5C%5C-2.196%2F4%20%3D%20r%5E%7B3%7D%20%5C%5Cr%20%3D%20%5Csqrt%5B3%5D%7B0.549%7D%20%5C%5Cr%20%3D%200.82)
where
a is the first term
r is the common ratio and
n is the nth term
_________________________________
given
a = 4
4th term = -2.196
let
common ratio of this sequence. be r
![4\ th \ term = ar^n-1\\-2.196 = 4r^{4-1} \\-2.196/4 = r^{3} \\r = \sqrt[3]{-0.549} \\r = -0.82](https://tex.z-dn.net/?f=4%5C%20th%20%5C%20term%20%3D%20ar%5En-1%5C%5C-2.196%20%3D%204r%5E%7B4-1%7D%20%5C%5C-2.196%2F4%20%3D%20r%5E%7B3%7D%20%5C%5Cr%20%3D%20%5Csqrt%5B3%5D%7B-0.549%7D%20%5C%5Cr%20%3D%20-0.82)
a) Find the common ratio of this sequence.
answer: -0.82
sum of infinity of geometric sequence is given by = a/(1-r)
thus,
sum to infinity of this sequence = 4/(1-(-0.82) = 4/1.82 = 2.2