The number that was left out is 70.
<h3>What is the number that was left out?</h3>
Average is the sum of a set of numbers divided by the total numbers in the data set.
Average = sum of numbers / total numbers
- Sum of numbers when there are 8 numbers = 56 x 8 = 448
- Sum of numbers when there are 7 numbers = 54 x 7 = 378
- Difference = 448 - 378 = 70
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Tammy's sample may not be considered valid because, on the first hand, it is said that she only asked students from her " Math Class".
If she wants to have a survey to find out the favorite subject of the students at her school, she must conduct a survey involving all the students in her school, not just in her class. What she did is just subjective. She should use a tally listing the different subjects and compare the number of students per subject. This way, she can have an objective representation of the least liked subjects and the most liked subjects of the students on her school.
Illustrating her survey through statistics may be more reliable and valid because it shows frequencies in which she can calculate easily and accurately the percentage of the number of students per subject, in a more objective manner.
Answer:
x = -3
General Formulas and Concepts:
<u>Pre-Algebra</u>
- Order of Operations: BPEMDAS
- Equality Properties
Step-by-step explanation:
<u>Step 1: Define equation</u>
5(x + 4) = -2(-4 - x) + 3
<u>Step 2: Solve for </u><em><u>x</u></em>
- Distribute: 5x + 20 = 8 + 2x + 3
- Combine like terms: 5x + 20 = 2x + 11
- Subtract 2x on both sides: 3x + 20 = 11
- Subtract 20 on both sides: 3x = -9
- Divide 3 on both sides: x = -3
<u>Step 3: Check</u>
<em>Plug in x to verify it's a solution.</em>
- Substitute: 5(-3 + 4) = -2(-4 - -3) + 3
- Simplify: 5(-3 + 4) = -2(-4 + 3) + 3
- Add: 5(1) = -2(-1) + 3
- Multiply: 5 = 2 + 3
- Add: 5 = 5
Here we see that 5 does indeed equal 5. ∴ x = -3 is a solution of the equation.
And we have our final answer!
-30 represents 30 meters below zero.
Zero represents sea level in this situation.
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