Hi Zahra, I've found a very simple and effective way of calculating percentages. 78% refers to 78 out of every 100, which can also be written as "0.78". Now, we can simply multiply 0.78 by your number (975) to get 760.5 students. Obviously, there isn't a half a student, so we round that number up to 761. So 761 out of 975 students do their homework before 10:00.
The mean of the data is 11
now we find the difference between the mean and each number
1, 2, 3, 0.5, 0.25, 1.25, 1.
now we square the numbers
1, 4, 9, 0.25, 0.0625, 1.
now we find the mean of the new numbers
which is 2.1875
2.1875 is your standard deviation.
Answer:
Step-by-step explanation:
22: 7/5
23: 15/4
24: 21/8
25: 9/2
26: 16/3
27: 13/7
28: 25/4
29: 32/9
30: 32/3
<span>(75 1/2 + 50 1/6 + 120 + 39 1/3)*5 = $1,425
Answer- 1,425</span>
B. A parallelogram is a rectangle.