Given that,
Colin buys a box of pasta that contains 823 cups of pasta.
He uses 212 cups to make dinner.
To find,
How much pasta is left?
Solution,
Left pasta = Total cups of pasta - used cups of pasta
= 823 - 212
= 611
Hence, 611 cups of pasta is left.
For a known standard deviation, the confidence interval for sample size = n is
![(x-z \frac{ \sigma }{ \sqrt{n}},x+x \frac{ \sigma }{ \sqrt{n} } )](https://tex.z-dn.net/?f=%28x-z%20%5Cfrac%7B%20%5Csigma%20%7D%7B%20%5Csqrt%7Bn%7D%7D%2Cx%2Bx%20%5Cfrac%7B%20%5Csigma%20%7D%7B%20%5Csqrt%7Bn%7D%20%7D%20%20%29)
where
x = average
n = sample size
![\sigma](https://tex.z-dn.net/?f=%20%5Csigma%20)
= stad. deviation
z = contant that reflects confidence interval
Let a = x
Let b =
![z \frac{ \sigma }{ \sqrt{n} }](https://tex.z-dn.net/?f=z%20%5Cfrac%7B%20%5Csigma%20%7D%7B%20%5Csqrt%7Bn%7D%20%7D%20)
From the given information,
a - b = 0.432 (1)
a + b = 0.52 (2)
Add (1) and (2): 2a = 0.952 => a = 0.476
Subtract (2) from (1): -2b = -0.088 => b = 0.044
Therefore, the confidence interval may be written as
(0.476 - 0.044, 0.476 + 0.044), or as
(0.476
![\pm](https://tex.z-dn.net/?f=%20%5Cpm%20)
0.044)
Answer: 180/540
Simplified term would be 1/3
The answer is b