Hi there!
We are given the equation:
x² - 2y = 7
To verify if each ordered pair is apart of the function, we can plug in their respective x and y values:
1. (5)² - 2(8) = 7
25 - 16 = 9 ≠ 7. This is NOT correct.
2. (-1)² - 2(-3) = 7
1 + 6 = 7. This is correct.
3. (-4)² - 2(-11.5) = 7
16 + 23 = 39 ≠ 7. This is NOT correct.
4. (1.2)² - 2(-2.78) = 7
1.44 +5.56 = 7. This is correct.
Thus, only 1 and 4 are the correct answers.
Answer:
the standard deviation increases
Step-by-step explanation:
Let x₁ , x₂, . . . , x₂₃ be the actual data observed by the student
The sample means = x₁ + x₂ + . . . , x₂₃ / 23
= 2.3hr
⇒
let x₁ , x₂, . . . , x₂₃ arranged in ascending order
Then x₂₃ was 10 and has been changed to 14
i.e x₂₃ increase to 4
Sample mean
therefore, the new sample mean is 2.47
2) For the old data set
the median is values
when we use the new data set only x₂₃ is changed to 14
i.e the rest all observation remain unchanged
Hence, sample median = remain unchange
sample median = 2.5hrs
The Standard deviation of old data set is calculated
The new sample standard sample deviation is calculated as
Now, when we compare (1) and (2) the square distance between each observation xi and old mean is less than the squared distance between each observation xi and the new mean.
Since,
(xi - 2.3)² ∑ (xi - 2.47)²
Therefore , the standard deviation increases
Answer:
The labor fee is $14.25, each quart of oil costs $2.25.
Step-by-step explanation:
Let $x be thee price of each quart of oil and $y be a flat fee for labor.
1. If the oil change for one car required 5 quarts of oil, then these 5 quarts cost $5x and together with a flat fee for labor it cost $25.50. Thus,
5x+y=25.50.
2. If the oil change for another car required 7 quarts of oil, then these 7 quarts cost $7x and together with a flat fee for labor it cost $30.00. Thus,
7x+y=30.00.
3. Subtract from the second equation the first one, then
Substitute it into the first equation:
The labor fee is $14.25, each quart of oil costs $2.25.