If we have 420 books for every 7 shelves and are looking for how many books are on 4 shelves, we need to set up fractional proportions.
We have 7 shelves for every 420 books, so we will have our first fraction like this:
7/420.
We also have 4 shelves for every x books, so our second fraction will be 4/x.
Set these fractions up as an equation.
7/420 = 4/x
To solve for x, we need to cross multiply the numerators of one fraction with the denominators of the other fraction.
In other words, multiply the top number of one fraction by the bottom number of the other question.
It should look like this:
7(x)
420(4)
7(x) = 7x
420(4) = 1680
Set your products up as an equation.
7x = 1680
Now to solve for x, we need to simplify.
Currently, x is being multiplied by 7.
To get x alone, divide 7x by 7.
Remember, what you do to one side of an equation, you must do to the other, so divide 1680 by 7.
7x / 7 = x
1680 / 7 = 240
You are left with:
x = 240.
For every 4 shelves you have 240 books.
I hope this helps!
If 3z=2z+5 and z=5, then you’d just plug the 5 in.
3(5)=2(5)+5 —> 15=10+5 —> 15=15
This statement is TRUE because 15 does equal 15.
I hope this helps. :)
So, if I understand correctly the prize before sales tax is 40 dollars and the sales tax is 8%. how much is this?
so the final prize is 40+3.2=43.2
Answer:
Step-by-step explanation:
Data provided
represent the sample mean in mg per deciliter of cholesterol level
represent the sample standard deviation
sample size
represent the value that we want to test
t would represent the statistic (variable of interest)
represent the p value for the test (variable of interest)
System of hypothesis
We need to conduct a hypothesis in order to check if the mean is higher than 53 mg per deciliter, the system of hypothesis would be:
Null hypothesis:
Alternative hypothesis:
The statistic is given by:
(1)
Calculate the statistic
Replacing into the formula we got:
P-value
We need to find first the degrees of freedom:
The p value for this case since we have a right tailed test is:
Answer:
1 8/9
Step-by-step explanation:
