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:
The length of JM is 40
Step-by-step explanation:
Since 7x+5 and 8x are both equal, we can make this equation:
7x+5=8x
-7x -7x
x=5
7(5)=35
35+5=40
- 56 ads jajjajahahahahajha
Hi there!
Pretty much, more means to add, so when you said, "10 more than 36", we immediately think addition. :)
36 + 10 = 46, right?
So, your answer is 46 :)
Hope this helps!
Message me if you need anything else, I'd be happy to answer any other questions you may have!