Answer:
Polly=30
Andy=60
Phoebe=180
Step-by-step explanation:
Polly=x
Andy=2x
Phoeby 3(2x)=6x
x+2x+6x=270
9x=270
x=30
Polly=x=30
Andy = 2x=60
Phoebe=6x=180
Answer:
The MAD of city 2 is <u>less than</u> the MAD for city 1, which means the average monthly temperature of city 2 vary <u>less than</u> the average monthly temperatures for City 1.
Step-by-step explanation:
For comparing the mean absolute deviations of both data sets we have to calculate the mean absolute deviation for both data sets first,
So for city 1:



Now to calculate the mean deviations mean will be subtracted from each data value. (Note: The minus sign is ignored as the deviation is the distance of value from the mean and it cannot be negative. For this purpose absolute is used)

The deviations will be added then.
So the mean absolute deviation for city 1 is 24 ..
For city 2:



Now to calculate the mean deviations mean will be subtracted from each data value. (Note: The minus sign is ignored)

The deviations will be added then.
So the MAD for city 2 is 11.33 ..
So,
The MAD of city 2 is <u>less than</u> the MAD for city 1, which means the average monthly temperature of city 2 vary <u>less than</u> the average monthly temperatures for City 1.
When applying indirect proofs, we assume the negation of the conclusion is true, and show that this assumption would lead to nonsense, or contradiction.
In our case we assume a is not smaller than 7, that is we assume a≥7.
a≥7 then, multiplying both sides by 3:
3a≥21, then, adding both sides 7:
3a+7≥28,
which is a contradiction because 3a+7 is smaller than 28.
So our assumption is wrong, which means the opposite of it is correct.
Answer: assume a≥7
Answer:
4x + 2
Step-by-step explanation:
x - 1 is adding an x and subtracting a 1 ,so
x + x + x + (x - 1) + 1 + 1 + 1
= x + x + x + x - 1 + 1 + 1 + 1 ← collect like terms
= 4x + 2