The box-and-whisker plot shows the weights, in kilograms, of randomly selected packages in a mail truck. Which of the following conjectures does the plot support?

A.
The median weight of the packages in the truck is about 50 kilograms.

B.
There are at least 100 packages in the truck.

C.
About three-fourths of the packages in the truck weigh less than 50 kilograms.

D.
Half of the packages in the truck weigh between 20 and 30 kilograms.

Question

The box-and-whisker plot shows the weights, in kilograms, of randomly selected packages in a mail truck. Which of the following conjectures does the plot support?
 
 A.
The median weight of the packages in the truck is about 50 kilograms.
 
 B.
There are at least 100 packages in the truck.
 
 C.
About three-fourths of the packages in the truck weigh less than 50 kilograms.
 
 D.
Half of the packages in the truck weigh between 20 and 30 kilograms.

thefluffmuncher · Answer

Graph: http://static.k12.com/calms_media/media/328500_329000/328818/1/b3cfd3b9400069180d81d8a65e01a50edd8faea6/MS_ALG_S2_07_04_quiz_Q1_question.gif

thefluffmuncher · Answer

how do i do this?

imstuck · Answer

Ok, look how your box-and-whisker plot is set up.  Are you familiar with these much?

thefluffmuncher · Answer

not really

thefluffmuncher · Answer

i just delved into the topic just now

imstuck · Answer

There are 3 separations in the big box.  The middle line in the big box is the median of whatever the data is.  Here it is the number of boxes as your box-and-whiskers, and the numbers along the bottom are the weights.  That middle line in the box is your median weight.  Aka the average weight.  Looking at your choices for the answers, the median weight does NOT fall at 50, it falls at 30.  So A is out.  Next look at B.  You don't really know much about how many boxes there are total because you are not told that.  You are only given the weights of the boxes so that is what your answer has to be in terms of.  You could have any number of boxes with an average weight of 30.  So it's not B.  C says that about 3/4 of the packages weigh less than 50.  If you look at your box-and-whiskers plot, ALL of them weight less than 50.  So it's not C.  Now it must be D due to the process of elimination, but let's see why.  D says that half the packages in the truck weigh between 20 and 30.  Well, since 30 is the median weight, or in other words the weight of about half of the packages, about 50% weigh between 20 and 30 (20 is where your lowest weight starts and 30 is your median weight, so the first 50% of the packages fall within the weight range of 20 and 30.)  I really hope this helped you.  These crazy things are supposed to make things easier....REALLY?