Answer is c , got it right
Answer:
10.4^2 = 108.16
Step-by-step explanation:
10.4^2 = 10.4 * 10.4
10.4 * 10.4 = (10 * 10.4) + (0.4 * 10.4)
(10 * 10.4) + (0.4 * 10.4) = (104) + (4.16)
(104) + (4.16) = 108.16
Answer: 1:5
Step-by-step explanation:
Given: The cost of every mirror is proportional to the cube of the mirror's radius.
i.e. ![\dfrac{\text{Cost of smallest mirror}}{\text{Cost of largest mirror}}=\dfrac{(\text{radii of smallest mirror}^3)}{\text{(radii of largest mirror)}^3}](https://tex.z-dn.net/?f=%5Cdfrac%7B%5Ctext%7BCost%20of%20smallest%20mirror%7D%7D%7B%5Ctext%7BCost%20of%20largest%20mirror%7D%7D%3D%5Cdfrac%7B%28%5Ctext%7Bradii%20of%20smallest%20mirror%7D%5E3%29%7D%7B%5Ctext%7B%28radii%20of%20largest%20mirror%29%7D%5E3%7D)
Their largest mirrors have radii of 5 meters and their smallest mirrors have radii of 1 meter.
Then,
![\dfrac{\text{Cost of smallest mirror}}{\text{Cost of largest mirror}}=\dfrac{1^3}{(5)^3}=\dfrac{1}{125}](https://tex.z-dn.net/?f=%5Cdfrac%7B%5Ctext%7BCost%20of%20smallest%20mirror%7D%7D%7B%5Ctext%7BCost%20of%20%20largest%20mirror%7D%7D%3D%5Cdfrac%7B1%5E3%7D%7B%285%29%5E3%7D%3D%5Cdfrac%7B1%7D%7B125%7D)
The ratio of the total cost of 25 of the company's smallest mirrors to the cost of one of the company's largest mirrors will be:
![\dfrac{\text{Cost of 25 smallest mirror}}{\text{Cost of largest mirror}}=\dfrac{25\times 1}{125}=\dfrac{1}{5}](https://tex.z-dn.net/?f=%5Cdfrac%7B%5Ctext%7BCost%20of%2025%20smallest%20mirror%7D%7D%7B%5Ctext%7BCost%20of%20largest%20mirror%7D%7D%3D%5Cdfrac%7B25%5Ctimes%201%7D%7B125%7D%3D%5Cdfrac%7B1%7D%7B5%7D)
Hence, the ratio of the total cost of 25 of the company's smallest mirrors to the cost of one of the company's largest mirrors = 1:5 .
Answer:
The 84% confidence interval for the population proportion that claim to always buckle up is (0.74, 0.80).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.
![\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}](https://tex.z-dn.net/?f=%5Cpi%20%5Cpm%20z%5Csqrt%7B%5Cfrac%7B%5Cpi%281-%5Cpi%29%7D%7Bn%7D%7D)
In which
z is the z-score that has a p-value of
.
They randomly survey 387 drivers and find that 298 claim to always buckle up.
This means that ![n = 387, \pi = \frac{298}{387} = 0.77](https://tex.z-dn.net/?f=n%20%3D%20387%2C%20%5Cpi%20%3D%20%5Cfrac%7B298%7D%7B387%7D%20%3D%200.77)
84% confidence level
So
, z is the value of Z that has a p-value of
, so
.
The lower limit of this interval is:
![\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.77 - 1.405\sqrt{\frac{0.77*0.23}{387}} = 0.74](https://tex.z-dn.net/?f=%5Cpi%20-%20z%5Csqrt%7B%5Cfrac%7B%5Cpi%281-%5Cpi%29%7D%7Bn%7D%7D%20%3D%200.77%20-%201.405%5Csqrt%7B%5Cfrac%7B0.77%2A0.23%7D%7B387%7D%7D%20%3D%200.74)
The upper limit of this interval is:
![\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.77 + 1.405\sqrt{\frac{0.77*0.23}{387}} = 0.8](https://tex.z-dn.net/?f=%5Cpi%20%2B%20z%5Csqrt%7B%5Cfrac%7B%5Cpi%281-%5Cpi%29%7D%7Bn%7D%7D%20%3D%200.77%20%2B%201.405%5Csqrt%7B%5Cfrac%7B0.77%2A0.23%7D%7B387%7D%7D%20%3D%200.8)
The 84% confidence interval for the population proportion that claim to always buckle up is (0.74, 0.80).
The answer is $51. If you take the original amount and subtract 15% from it you get $51.