John had 7 red marble and 5 blue marble in a box. Today, he put some marble in the box and the ratio is 10 red to 19 total. How many blue marbles does he put today in the box?

He added 14 blue marbles to the box today

10 - 19 =9 answer 9 blue marbles

Step-by-step explanation:

solution:

as, mean is defined as sum of all the observations divided by total number of observations.

and , median is mid value of the data whether arranged in ascending order or descending order.

consider, roadsters:

2,3,4,5,6,7,8,9

mean =

also, median= , because number of observations is even, so median is mean of two mid values.

now, coming to bandits

2,3,4,5,6

mean =  

median = 4, as number of observations is odd.

so, roadsters has greater median as well mean than bandits.

→option a is true about the repairs performed on 2 types of cars:

bandits have lower median and mean than roadsters.