Answer:
a) X[bar]=93
b)S=5.39
Step-by-step explanation:
Hello!
<em>A simple random sample of 5 months of sales data provided the following information: Month: 1 2 3 4 5 Units Sold: 94 100 85 94 92 </em>
<em />
<em>a. Develop a point estimate of the population mean number of units sold per month. </em>
The variable of interest is:
X: Number of sales per month.
A random sample of n=5 months was taken, for each month, the number of units sold was recorded. To calculate the mean of the sample you have to add all the observed frequencies (Units Sold) by the sample size (n)
X[bar]= ∑X/n= 465/5=93
You can say that, on average, 93 units were sold over the 5-month period.
<em>b. Develop a point estimate of the population standard deviation.</em>
To calculate the sample standard deviation you have to calculate the variance and then its square root:
![S^2= \frac{1}{n-1}[sumX^2-\frac{(sumX)^2}{n} ]](https://tex.z-dn.net/?f=S%5E2%3D%20%5Cfrac%7B1%7D%7Bn-1%7D%5BsumX%5E2-%5Cfrac%7B%28sumX%29%5E2%7D%7Bn%7D%20%5D)
∑X= 465
∑X²= 43361
![S^2= \frac{1}{4}[43361-\frac{(465)^2}{5} ]= 29](https://tex.z-dn.net/?f=S%5E2%3D%20%5Cfrac%7B1%7D%7B4%7D%5B43361-%5Cfrac%7B%28465%29%5E2%7D%7B5%7D%20%5D%3D%2029)
S= √29= 5.385≅ 5.39
I hope this helps!
[x = amount earning 6% annually.]
(8000-x) = amount earning 15% annually
Then we set up our equation which is a sum of the 15% return and the 6% return and we let that sum equal our desired return on investment ($930). Then solve for x.
(8000-x)*.15 + x*.06 = 930
1200 - .15x + .06x = 930
.09x = 270
x = 3000.
Therefore, you should invest $3000 at 6% and $5000 at 15% to earn $930 annually.
Answer:
8.4 miles a minute
Step-by-step explanation:
42÷5 = 8.4 a minute