Answer:
Step-by-step explanation:
Variance is the sum of squares of all items x from mean. i.e
Variance = 
Being the sum of squares variance can never be negative irrespective of mean being negative.
Std deviation is the square root of variances. This will thus be less than variance if variance >1 other wise std deviation will be bigger than variance.
Hence option d is right.
Answer:
The loan must have been $2500 originally. i think
<span>Let’s assume the number of problems as P
Student did his homework = (3/5) P + 8
Father did the homework = (1/5) P + 7
So the sum of the both equations is equal to P
=> (3/5) P + 8 + (1/5) P + 7 = P
=> (4/5) P + 15 = P
=> 4P + 75 = 5P
=> P = 75
Problems they solve together are 75 problems.</span>