Answer:
Step-by-step explanation:
For this case we can calculate all the questions with the following table:
Class Midpoint(Xi) fi Xi*fi Xi^2 *fi
____________________________________
0-3 1.5 6 9 13.5
3-6 4.5 6 27 121.5
6-9 7.5 11 82.5 618.75
9-12 10.5 21 220.5 2315.25
12-25 18.5 5 18 1711.25
_____________________________________
Total 49 431.5 4780.25
We can calculate the expected value with the following formula:
And if we replace we got:
We can calculate the sample variance with the following formula:
And replacing we got:
And the deviation would be just the square root of the variance like this:
Answer:
Yes
Step-by-step explanation:
The answer would be 13 because 26 divided by 2 is 13.
Answer:
88 times
Step-by-step explanation:
The two comes up 20 out of 50 times
We don't know how many times 2 will come up if the die is rolled 220 times. We can, however, set up a proportion
20/50 = x/220 Cross multiply
50x = 20 * 220 Combine the right
50x = 4400 Divide by 50
50x/50 = 4400/50 Do the division
x = 88 times.
Answer:
-10
Step-by-step explanation:
since the answer is positive, we need a negative number, if we use -10,two negatives makes a positive, so it becomes
-8 +10=2
Answer:
Sessions needed= 12
Step-by-step explanation:
Giving the following information:
Total hours= 12 hours
Practice= 3/4= 0.75 of an hour
Already practiced= 3 hours
<u>First, we need to determine how many minutes does she practice each session:</u>
Minutes per session= 0.75*60= 45 minutes
<u>Now, we divide the total practice in minutes required for the minutes per session:</u>
Sessions needed= (9*60) / 45
Sessions needed= 12