6th grade math please help
2 answers:
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Answer:
456
Step-by-step explanation:
Let X be the SATscore scored by the students
Given that X is normal (1000,200)
By converting into standard normal variate we can say that
is N(0,1)
To find the top 10% we consider the 90th percentile for z score
Z 90th percentile = 1.28
i.e. only students who scored 456 or above only should be considered.
That's a question about percentage.
One way to represent percentage is using decimal number. In this way, 1 is equivalent to 100% and the other less percentages using numbers between 0 and 1.
Examples:
- 90% is equivalent to 0,90.
- 5% is equivalent to 0.05. It's not 0.5 because 0.5 is equivalent to 50%.
- 13.17% is equivalent to 0.1317.
- 245% is equivalent to 2.45.
If we want to know the percentage of a number, we should multiplacate the number by the porcentage in the decimal number form.
Examples:
- 55.90% of 200 is equal to:
- 360% of 88 is equal to:
In our problem, we have a phone with a increase of 7%. To solve that, it's important to perceive that $230 is equal to 100% and with a increase of 7%, we will pay 107%.
107% in the decimal number form is 1.07. With that information, we should multiplicate 1.07 by the original value and we will find the answer.
We know that , therefore, the total cost of the phone after tax is $246.1.
I hope I've helped. :D
Enjoy your studies. \o/