Answer:
0.998 is the probability that the average money spent by a sample of 40 shoppers is within $10 of the actual population mean.
Step-by-step explanation:
We are given the following information in the question:
Standard Deviation, σ = $21.51
We are given that the distribution of average money spend is a bell shaped distribution that is a normal distribution.
Formula:
We have to find:
P( average money spent is within $10 of the actual population mean.)
Calculation the value from standard normal z table, we have,
Answer:
9m+6m^2n
Step-by-step explanation:
12mn-3mn=9mn
4m^2n+2m^2n=6m^2n
==> 9m+6m^2n
or rewrite as 3m(3+2mn)
Answer:
52
Step-by-step explanation:
Given that :
Mean (m) = 78
Standard deviation (s) = 13
Score that is 2 standard deviations below the mean
Using the relation :
Zscore = (x - m) / s
2 standard deviations below the mean means a Zscore of - 2
Hence,
-2 = (x - 78) / 13
Cross multiply
-2 * 13 = x - 78
-26 = x - 78
x = - 26 + 78
x = 52
Score which is 2 standard deviations below the mean is 52
Answer:
y = 2.31x + 309.35
Step-by-step explanation:
Whenever you are checking for a best fitting equation you want to check if it has a constant slope. If it does then the relation is linear and super easy.
So, since the t values are increasing by the same amount you want to see if the y values are too. And they are, each population entry is increasing by 2.31, this is the slope.
Also, keep in mind you can caluclate slope with the equation 
here x is replaced by t though.
Now, since we know it's linear and we know the slope we can find the equation with the formula y - y1 = m(x - x1) where again, x is replaced by t and m is the slope 2.31
I am just going to use the first point. so x1 = t1 = 0
y - 309.35 = 2.31(x-0)
y = 2.31x + 309.35
Let me know if there was something you didn't understand.
