Answer:
https://www.gstatic.com/education/formulas2/355397047/en/slope_of_a_line.svg
Step-by-step explanation:
To find the slope, you divide the difference of the y-coordinates of 2 points on a line by the difference of the x-coordinates of those same 2 points.
Answer:
The 80% confidence interval for the population mean is between 28.32 characters and 31.68 characters.
Step-by-step explanation:
We have the standard deviation for the population, so we can use the normal distribution. If we had the standard deviation for the sample, we would have to use the t-distribution.
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so 
Now, find the margin of error M as such

In which
is the standard deviation of the population and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 30 - 1.68 = 28.32 characters.
The upper end of the interval is the sample mean added to M. So it is 30 + 1.68 = 31.68 characters.
The 80% confidence interval for the population mean is between 28.32 characters and 31.68 characters.
Answer: She has to score a minimum of 92 marks to take her average to 80
Step-by-step explanation:
Let the equation be
Three months total = 76 x 3 = 228
(x + 228) / 4 = 80
x + 228 = 80 x 4
x = 320 - 228
x = 92
Answer:

Step-by-step explanation:
we have


we know that
To find the function that represent the total amount Jack and Suzie will save in x years, adds f(x) and g(x)
so

^{x}](https://tex.z-dn.net/?f=f%28x%29%2Bg%28x%29%3D%5B1%2C000%2B800%5D%281.015%29%5E%7Bx%7D)
