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!
1-(-8)
1+8 (add a line change the sign)
=9
Answer:
7x - 6y = 16
y = (-5)
using substitution method
7x - 6(-5) = 16
7x +30 = 16
7x = 16 - 30
7x = 14
x = 14/7
x= 2
Answer:
80 square yards
Step-by-step explanation:
We know we have a width of 8 yards and a perimeter of 36.
how I figured it out was:
36=(8*2) * (x*2)
8*2=16
36-16=10
So now we know the length and width.
area of a rectangle is lw (length * width)
10*8=80.
Answer:
Number of children = 386
Number of adults = 287
Step-by-step explanation:
Let
x = number of children
y = number of adults
x + y = 673 (1)
1.75x + 2y = 1249.50 (2)
From (1)
x = 673 - y
Substitute x = 673 - y into (2)
1.75x + 2y = 1249.50
1.75(673 - y) + 2y = 1249.50
1177.75 - 1.75y + 2y = 1249.50
- 1.75y + 2y = 1249.50 - 1177.75
0.25y = 71.75
y = 71.75/0.25
y = 287
Substitute y = 287 into (1)
x + y = 673
x + 287 = 673
x = 673 - 287
x = 386
Number of children = 386
Number of adults = 287