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:
-7
Step-by-step explanation:
5+-7
Answer: division
Step-by-step explanation:
Answer:
18 boys and 15 girls
Step-by-step explanation:
Since the ratio is 6:5 and there are 18 boys, you do 18/6=3
Then you do 5*3=15
X=-2 I think my bad if u got it ring