Need help with option 1 or 2
1 answer:
Option 2.
1. Simplify 7 + (12 - 9) + 7 × 3(8 - 5)
According to the Order of Operations, contents of parentheses are evaluated first. This gives
... 7 + 3 + 7 × 3 × 3
Then multiplication and division are performed left to right.
... = 7 + 3 + 21 × 3
... = 7 + 3 + 63
Followed by addition and subtraction left to right.
... = 10 + 63
... = 73
A Google search box can be relied upon to do the operations in the correct order.
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2. When the expression is rewritten, a different result is obtained. This is because the operations indicated by the second set of parentheses are altered.
... (7 + 12) - 9 + (7 × 3)8 - 5
... = 19 - 9 + 21 × 8 - 5
... = 19 - 9 + 168 - 5
... = 10 + 168 - 5
... = 178 - 5
... = 173
In the first expression, both +8 and -5 are multiplied by 21. In the rewritten expression, only +8 is multiplied by 21.
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Answer:
- <u>The correct statement is the first one: </u><u><em>The number of blue-eyed students in Mr. Garcia's class is 2 standard deviations to the right of the mean</em></u><em> </em>
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Explanation:
To calculate how many<em> standard deviations</em> a particular value in a group is from the mean, you can use the z-score:
Where:
is the number of standard deviations the value of x is from the mean
is the mean
is the standard deviation
Substitute in the formula:
Which means that <em>the number of blue-eyed students in Mr. Garcia's class is 2 standard deviations</em> above the mean.
Above the mean is the same that to the right of the mean, because the in the normal standard probability graph the central value is Z = 0 (the z-score of the mean value is 0), the positive values are to the right of the central value, and the negative values are to the left of the central value.
Therefore, the correct statement is the first one: <em>The number of blue-eyed students in Mr. Garcia's class is 2 standard deviations to the right of the mean, </em>