Answer:
Step-by-step explanation:
I have an expression

floating around in my head; let's see if it makes sense.
The variance of binary valued random variable b that comes up 1 with probability p (so has mean p) is

That's for an individual sample. For the observed average we divide by n, and for the standard deviation we take the square root:

Plugging in the numbers,

One standard deviation of the average is almost 2% so a 27% outcome was 3/1.9 = 1.6 standard deviations from the mean, corresponding to a two sided probability of a bit bigger than 10% of happening by chance.
So this is borderline suspect; most surveys will include a two sigma margin of error, say plus or minus 4 percent here, and the results were within those bounds.
Equation: y=-5x+100, where x is the number of hours and y is the battery percentage
The slope is -5, meaning she loses 5% of battery per hour
:)
Simplify:
5(a + 5) + -3 = 3(2 + -1a)
Reorder the terms:
5(5 + a) + -3 = 3(2 + -1a)
(5 * 5 + a * 5) + -3 = 3(2 + -1a)
(25 + 5a) + -3 = 3(2 + -1a)
Reorder the terms again:
25 + -3 + 5a = 3(2 + -1a)
Combine like terms:
]25 + -3 = 22
22 + 5a = 3(2 + -1a)
22 + 5a = (2 * 3 + -1a * 3)
22 + 5a = (6 + -3a)
Solve:
22 + 5a = 6 + -3a
To solve for variable 'a':
You have to move all terms containing A to the left, all other terms to the right.
Then add '3a' to each side of the equation:
22 + 5a + 3a = 6 + -3a + 3a
Combine like terms:
5a + 3a = 8a
22 + 8a = 6 + -3a + 3a
Combine like terms again:
-3a + 3a = 0
22 + 8a = 6 + 0
22 + 8a = 6
Add '-22' to each side of the equation.:
22 + -22 + 8a = 6 + -22
Combine like terms:
22 + -22 = 0
0 + 8a = 6 + -22
8a = 6 + -22
Combine like terms once more:
6 + -22 = -16
8a = -16
Divide each side by '8'.
a = -2
Simplify:
a = -2
Answer: a=-2
Hope I could help! :)