Answer:
21, 144, 12
Step-by-step explanation:
Given that a sample of 30 distance scores measured in yards has a mean of 7, a variance of 16, and a standard deviation of 4.
Let X be the distance in yard.
i.e. each entry of x is multiplied by 3.
New mean variance std devition would be
E(3x) = 
Var (3x) = 
Std dev (3x) = 
Thus we find mean and std devition get multiplied by 3, variance is multiplied by 9
It would be the distributive property. :)
Step-by-step explanation:
Let the original speed of the train be x km/h.
Time taken to cover a distance of 360 km = 360/x hours.
New speed of the train = (x+5) km/h.
Time taken to cover a distance of 360 km at new speed = 360/x+5 hours.
Since, the train takes 1 hour less time,
∴360/x - 360/ x+5 = 1
⇒360 (5) = x² + 5x
⇒1800 = x² + 5x
⇒x² + 5x - 1800 = 0
⇒x² + 45x - 40x - 1800 = 0
⇒x (x+45) - 40( x +45) = 0
⇒(x+45) (x-40) = 0
⇒x = (-45), 40
But since speed cannot be in negative.
∴x = 40 km/hr.
Hence, the original speed of the train is 40 km/h.
Its alright dude just gotta work hard and study i know you can do it
Are you talking about Halloween?
NVM can you delete that?I didn't read the begining
