Answer:
The correct option is b.
Step-by-step explanation:
The formula for standard deviation is
where, is mean of the data and n is number of observation.
The variance of a stock's returns can be calculated by the above formula.
Variance of stock's returns is the average value of squared deviations from the mean.
Therefore the correct option is b.
Answer:
y = - x + 1
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 )
Rearrange - 4x + 4y = 4 into this form by adding 4x to both sides
4y = 4x + 4 ( divide all terms by 4 )
y = x + 1 ← in slope- intercept form
with slope m = 1
given a line with slope m then the slope of a line perpendicular to it is
= -
= -
= - 1, thus
y = - x + c ← is the partial equation
To find c substitute (- 4, 5) into the partial equation
5 = 4 + c ⇒ c = 5 - 4 = 1
y = - x + 1 ← equation of perpendicular line