Answer:
a) x = 80.40
s = 29.54
b) lower limit = 69.53
upper limit = 91.27
Step-by-step explanation:
The mean price is:
The standard deviation is
![s=\sqrt{\frac{1}{n-1}\sum(x_i-\bar X)^2}=\sqrt{\frac{1}{19}[(50-80.4)^2+...+(70-80.4)^2]} \\\\s=\sqrt{\frac{15,471}{19} }=\sqrt{814.25} =29.54](https://tex.z-dn.net/?f=s%3D%5Csqrt%7B%5Cfrac%7B1%7D%7Bn-1%7D%5Csum%28x_i-%5Cbar%20X%29%5E2%7D%3D%5Csqrt%7B%5Cfrac%7B1%7D%7B19%7D%5B%2850-80.4%29%5E2%2B...%2B%2870-80.4%29%5E2%5D%7D%20%5C%5C%5C%5Cs%3D%5Csqrt%7B%5Cfrac%7B15%2C471%7D%7B19%7D%20%7D%3D%5Csqrt%7B814.25%7D%20%3D29.54)
We have to calculate a 90% CI for the mean.
The z-value for a 90% confidence interval is z=1.645.
The margin of error is:
The 90% CI is
So what you want to find is: what number times 120% is $324.00. (IT is 120% percent because it is the original <em>plus</em> the new percent) Simply set it up like so:
SN *120% = $324.00
Now turn the percent into a decimal:
SN * 1.20 = $324.00
Now divide $324.00 by 1.20
SN = $270
The original value of the basketball player's autograph was 270 dollars!
Hope that helps!
greatest common factor ..... what factor(s) do these two terms have in common?
3y² contains the following factors: 3 · y · y
-4y contains the following factors: -1 · 4 · y
Answer: y
Divide 2 by 74 and simplify into brackets
It is false that the area of a person's yard can be measured in cubic feet. It is always measured in square feet, because cubic feet add another dimension, which is height, and height is not measured in a yard.
