Remember you can do anything to an equation as long as you do it to both sides
a=age
500 reduced by 2 times a is equal to 388
500-2a=388
minus 500 both sides
-2a=-112
divide both sides by -2
a=56
you are 56
Precision is more like consistency. Take a rifle range for example. Sure, all the shots may be off centered, but if they're tightly grouped together, it shows that the shooter had precision in their shooting. Accuracy is how close to spot on the attempts or shots generally are. They would end up more towards the center, but a little more spread out.
The new mean is 66.09
<u>Explanation:</u>
Mean weight of 20 students = 65kg
One student with 88kg entered the room.
New mean = ?


The above equation can further be written as:

New mean = 
= 66.09
Therefore, the new mean is 66.09
A) 42,000m divided by 2 1/3 = 18,000m divide by 1000m to get km = 18km/hr
B) 18,000m divided by 60 to get minutes = 300m divide by 60 to get seconds = 5m/sec.