1/3+2/5+4/3+3/5=8/3
Steps
A double negative makes a positive.
So, change all double negatives to positives (to simplify it)
1/3 + 2/5 + 1+1/3 + 3/5
What's the least common denominator here?
Yes, it is 15!
Change the fractions to that denominator
5/15 + 6/15 + 1+5/15 + 9/15
change 1+5/15 to 20/15, then add the fractions
Result: 40/15
Divide numerator and denominator both by the greatest common factor:5
8/3
Answer : 7.2 hours
Step by Step Explanation: 12 divided by five equals 2.4
2.4 times 3 equals 7.2
Answer:

Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
represent the sample mean for the sample
population mean (variable of interest)
s represent the sample standard deviation
n represent the sample size
Solution to the problem
The confidence interval for the mean is given by the following formula:
(1)
For this case the confidence interval is given by (6.55,8.15). And we can estimate the margin of error with this formula since the confidence interval is symmetrical:

Answer:
30cm
Step-by-step explanation:
Assuming that the thickness of the books is 2cm (This is a reasonable assumption, as books are almost always longer and wider than they are thick, and assuming that the books are stacked flat on top of one another, faces up or down, and not sideways, the question becomes 'What is the height of 15 books stacked on top of one another, if each book is 2cm thick?' The answer to this question is 15*2 or 30.