1. Let hardcover books = X
Paperback books would be 4x -3 ( 3 less than 4 times)
Now you have:
X + 4x-3 = 447
Simplify:
5x - 3 = 447
Add 3 to each side:
5x = 450
Divide both sides by 5:
x = 450/5
x = 90
He has 90 hardcover books.
2. 300 miles / 25 miles per gallon = 12 gallons of gas.
12 gallons x $$ per gallon = $48 dollars
3. Subtract base pay from total:
1916 - 800 = 1,116 worth of commissions.
Divide commissions by percentage:
1116 / 0.09 = $12,400 total sales.
4.
Find the median of the heights: 65-50 = 15. 15/2 = 7.5
Median = 50+7.5 = 57.5
The equation would be |h-57.5| < 7.5
Answer:
5 classes.
Step-by-step explanation:
You can use the 
rule to determine the number of classes for a frequency distribution.
The rule says that 
where
is the number of classes
is the number of the data points
We know that the number of data points is = 20.
Next, we start searching for so that we can get a number 2 to the that is larger that the number of data points.
This suggests that you should use 5 classes.
Answer:P(BBR) = 1/2 × 25/51 × 26/50 = 13/102 if cards are not replaced.
P(RBB) = 1/2 × 26/51 × 25/50 (simplified 1/2) = 13/102
P(BRB) = 1/2 × 26/51 ×25/50 (simplified 1/2) = 13/102
Step-by-step explanation: P(B) at first step is 26 cards out of a possible 52 therefore 26/52 (or simplified 1/2). We then have 25 black cards left out of a possible 51 therefore 25/51. The final card then has to be red to meet the criteria, we have 26 red cards still out of a possible 50 therefore 26/50.
This would be an example of binomial probability as at each step there are only 2 options R or B.
Answers:
11. 48%
12. 25%
13. 36%
15. 93%
16. 99%
17. 0.16%
18. 160%
19. 85%
Work for 19:
The chart is incorrect because it calculates 40% of 34 instead of 40 percent of x (we got 85% for our answer but I'm using x as the unknown number) results in the number of 34.
Percentage of 40% of what number = 34?
40% of what number = 34 is equivalent to: 40% × ? = 34
--------------------------
40% × ? = 34
? =
34 ÷ 40% =
34 ÷ (40 ÷ 100) =
(100 × 34) ÷ 40 =
3,400 ÷ 40 =
85
Proof:
If 40% × 85 = 34 =>
Divide 34 by 85...
... And see if we get as a result: 40%
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20. 21 students
Step-by-step explanation:
I hope I helped, and I always appreciate brainliest!!! ;)
Answer: where is the homework that is needing help
