For this case we have the following expression:
To verify the answer we have:
Multiplying both sides of the equation by -14:
Thus, the answer can be verified with:
Answer:
The mean ( average ) is given as 1200 hours.
The standard deviation is 200, sample size is 100.
Find the standard error:
√(200^2 / 100) = 20
Now calculate the confidence interval. For 95% the Z number is 1.96
Multiply Z by the standard error:
1.96 x 20 =39.2
Now find the range that the mean should be within:
1200 - 39.2 = 1160.8
1200 + 39.2 = 1239.2
The samples should be between 1160.8 and 1239.2 for a 95% confidence interval.
Since the average was 1050, which is below 1160.8 the bulbs are not in compliance.
12+12 is 24, 24+24 is 48, and 48+4 is 52. Hope this helps!
Since both the expressions in x are equal to y then they are equal to each other, so
-2x + 3 = 13x - 4
-15x + 3 = -4
-15x = -7
x = 7/15
and y = -2(7/15) + 3 = 31/15 = 2 1/15
Step-by-step explanation:
you drew already the right things, you have everything.
so, what is the problem ?
the most common form of line equation is
y = ax + b
a is the slope of the line. it is expressed as the ratio
y coordinate change / x coordinate change
when going from one point to the other.
b is the y-intercept (the y value when x = 0).
once we have the slope, we get b by using the coordinates of one of the given points as x and y in the equation and solve for b.
so, for the 2 marked points you showed correctly the differences :
x changes by +8 (from -4 to 4).
y changes by -2 (from 3 to 1).
so the slope is -2/+8 = -1/4
the y-intercept we also see directly in the chart : +2.
