To find a percentage of a number we multiply the percentage times the number and get the result, here we have the percentage and the result and need to find out which number it corresponds to, lets write an equation to do so and keep in mind that the percentage itself can be written in a different way:
225% = 225 out of 100 = 225/100
So we have this equation, where we call x the number we are looking for:
<span>(225%)(x) = 81
</span>(225/100)(x) = 81
so we solve for x:
225x = 81*100 = 8100
x = 8100/225
x = 36
The original number is 36, hence 225% of 36 is 81
Answer: the actual amount that Luke paid including tax is $55.65
Step-by-step explanation:
The initial price of the jacket is $75.
Luke bought a jacket that was 30% off the cost. This means that the amount of discount on the Jacket is
30/100 × 75 = 0.3 × 75 = $22.5
The price of the jacket after the discount had been applied is
75 - 22.5 = $52.5
He paid sales tax of 6% after the discount had been applied. This means that the amount of sales tax that he paid on the jacket is
6/100 × 52.5 = 0.06 × 52.5 = 3.15
Therefore, the actual amount that Luke paid including tax is
52.5 + 3.15 = $55.65
Answer:
(3x - 14) = (2x+ 10) { Because the angles are vertically opposite to each other}
3x-2x= 14+10
x=24
Answer:
Where 
and 
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability using the complement rule:
Step-by-step explanation:
Previous concepts
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".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the variable of interest of a population, and for this case we know the distribution for X is given by:
Where and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability using the complement rule:
