Answer:
Step-by-step explanation:
The given data set is:
Week 1: 600
Week 2: 300
Week 3: 500
Week 4: 900
The following are the steps to find the standard deviation:
Step 1. Jim enters the data and calculates the average or mean.

Step 2. Jim calculates the deviation from the mean by subtracting the mean from each value.
Data value (x) 
600 25
300 -275
500 -75
900 325
Step 3. Jim squares each deviation to remove negative signs.
Data value (x) 
600 625
300 75625
500 5625
900 105625
Step 4. Jim sums the squares of each deviation and divides by the count for the variance.

Step 5.Jim takes the square root of the variance to find the standard deviation.

Answer:
30 strawberry sundaes.
Step-by-step explanation:
We know there is a total of 70 sundaes.
3 sundaes will be strawberry.
4 sundaes will be choclate.
When you add 3 and 4 together, you get 7. This is your total ratio.
So 3/7 of the sundaes are strawberry.
And 4/7 of sundaes are choclate.
We know there is a total of 70 sundaes.
The total ratio we figured out is 7.
If the total sundaes is 70, and the total ration is 7. Then the total sundaes is 10 times bigger than the ratio.
This means we need to multiply the 3 strawberry sundaes and 4 choclate sundaes by 10.
3*10=30
4*10=40
So there are 30 strawberry sundaes and 40 choclate sundaes.
We need to find the strawberry sundae amount, so the answer is 30.
Hope this helps!
Answer:
Step-by-step explanation:
a - 2.5 = 4.5
2.5 = 2.5
a = 7.0 or 7
7.0 - 2.5 = 4.5
4.5 = 4.5