B=books
Sold half of book: b/2
Bought six more: b/2+
Now has 12: b/2+6=12
Subtract 6 on both sides: b/2+6-6=12-6
b/2=6
Multiply both sides by 2: b=12
Answer= 12 books
Answer:
72.69% probability that between 4 and 6 (including endpoints) have a laptop.
Step-by-step explanation:
For each student, there are only two possible outcomes. Either they have a laptop, or they do not. The probability of a student having a laptop is independent from other students. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
A study indicates that 62% of students have have a laptop.
This means that 
You randomly sample 8 students.
This means that 
Find the probability that between 4 and 6 (including endpoints) have a laptop.






72.69% probability that between 4 and 6 (including endpoints) have a laptop.
4.5/3= 1.5
It is 1.5 times bigger than the smaller triangle.
So,
5*1.5= 7.5
x= 7.5
I hope this helps!
~kaikers
Well, you have to be given an interval. That is not an interval.
You should be given something like

If you add those fractions up you'll just get a point on the number line.
Find the LCD for all of them which is 9/6 - 4/6 + 3/6 = 8/6 = 2/3
You'll end up with a point on 2/3
Heads or tails lands 1 time in 1 coin flip