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
Answer:
There are 180 degrees in a triangle so it is 80 degrees
Answer: 8%
Step-by-step explanation: I BELIVE that the way you figure these things if devision, so, 80/10=8 :)
Answer:
Opens up.
Step-by-step explanation:
See the 2 in front of the x? If that's positive, it opens up. If it's negative, it opens down.
The answer to this question is False
