The first blank is proportional because <span>two quantities is one in which the two quantities vary directly with one and other. </span>If<span> one item is doubled, the other, related item is also doubled. Because of this, it is also called a direct variation. </span>
(a) Brand X median = 13
Brand Y median = 16
Median is the center dot in the shaded box (in blue color). Look at the Time (h) axis for their values. For Brand X it is 13 whereas for the Brand Y it is 16
(b) If we compare their median values we can see that the difference is 3 hours (16-13 = 3). It means that the Brand Y battery will last longer compared to Brand X battery as Brand Y lasts for 16 hours whereas Brand X battery lasts for 13 hours.
(8)(2)+4(8)(-5)(2)(2)
The answer is -624
The the sum of this problem is -2. I hope I helped you! :D