Answer:
The mean is 80 and the standard deviation is 20. Therefore we have
65 is 0.75 standard deviation below the mean.
Step-by-step explanation:
z = 
Since 85 is 0.25 standard deviations above the mean we have
or 0.25·σ = 85 - μ......1
1.5 = 
or 1.5·σ = μ - 50..............2
From 1 we have σ = 340 - 4·μ substituting into 2 gives
1.5·(340 - 4·μ) = μ - 50 ⇒ 510 - 6·μ = μ - 50
7·μ = 560 or μ = 80
Therefore σ = 340 - 4·μ = 340 - 4·80 = 20
A value, x, 0.75 standard deviation below the mean is given by
0.75 = 
which gives 15 = 80 - x or
x = 65.
a.
Circle W centre is (-3,0) - (0,-2)* = (-3,-2)
*note that the centre of the circle W is going down by 2 units this only affects the y axis hence the substraction
A dilation of a factor of 2 does not change the centre of the circle rather the radius ( the size of the circle decreases and hence the radius)
So now the radius becomes 8 UNITS/2 = 4UNITS
From the statements given,neither is correct
Answer:
10
Step-by-step explanation:
7(4)+2(2)-8(1.5)/2
28+4-12/2
20/2
10
Answer:
y = 3x - 27
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
Here m = 3 , then
y = 3x + c ← is the partial equation
To find c substitute (6, - 9) into the partial equation
- 9 = 18 + c ⇒ c = - 9 - 18 = - 27
y = 3x - 27 ← equation of line
