Answer:
Let p represent the # of pages in the book. Then, Nora has already read 0.30p pages and has 0.70p pages left to read.
If she reads 25% pages/night, that means reading 0.25(0.70)p pages per night, or 17.5 pages/night. If 28% p/n, that means 0.28(0.70)p pages/night, or 19.6p pages/night.
How many nights will it take Nora to finish the book if she reads 25% of 7/10 of the book per night? Without any calculations, we can answer this by "4 nights, since she reads 1/4 of the unread portion of the book per night."
If she reads 28% of 7/10 of the book per night, that will require fewer nights:
First night: 28%
Second night: 28%
Third night: 28%
Total: 3(28%) = 84%
This leaves 16% to read on the final night.
This is one interpretation of what I think is a poorly worded question.
The author of this question might have meant reading 25% of the remaining unread pages per night, which leads to a different answer.
Answer:
Factoring in groups is like breaking it apart piece by piece and takes more steps.
Factoring the difference of two squares takes few steps and is easier.
Answer:
The answer is 7/24.
Step-by-step explanation:
I attached a picture, but I'll try to walk through it here.
1) A negative and a negative makes a positive, so h becomes positive.
2) I added 7/8 to both sides, in order to "isolate the variable", which simply means to get h by itself, on one side of the equation (you'll likely hear it said both ways).
3) I multiplied 7/8 by 3/3, and multiplied -7/12 by 2/2. This is known as a common denominator, which in this case is 24. You can only add and subtract fractions that have a common denominator.
4) Multiply both of the fractions to get 21/24 + (-14/24). "Adding a negative" is the same thing as subtracting.
5) 21 - 14 = 7, and since our denominators are the same, the answer is 7/24.
You can confirm the answer by substituting, or "plugging" 7/24 into your original equation, in place of h.
Answer:
c. 9.5 lb < mu < 11.1 lb.
Step-by-step explanation:
Confidence interval can be stated as M±ME where
- M is the sample mean (10.3)
- ME is the margin of error
margin of error (ME) around the mean can be calculated using the formula
ME=
where
- z is the corresponding statistic in 95% confidence level (1.96)
- s is the standard deviation of the sample (2.4)
- N is the sample size (37)
Putting thesenumbers in the formula we get:
ME=
≈ 0.7733 ≈ 0.8
Then the 95% confidence interval would be 10.3 ± 0.8
