Scores on the critical reading part of the sat exam in a recent year were roughly normal with mean 495495 and standard deviation 118118 . you choose an srs of 100 students and average their sat critical reading scores. if you do this many times, the standard deviation of the average scores you get will be close to 118100=1.18118100=1.18 . 118100√=11.8118100=11.8 . 118100√=1.09118100=1.09 . 118118 .

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.

the correct answer is 5 6 and 7