The following table shows ice cream sales (y) with respect to the temperature for the day (x). which of the following is most likely to be the equation of the trend line?
temperature ice cream cones
(fahrenheit) sold
70 5
81 30
84 40
95 54
the answer is y=2x-130

We are given a set of data for temperature vs Ice Cream cones. Plotting the two sets of values and generating a trendline would produce the image I've attached. 
The trendline is given by the equation y = 2x + 131

The major difference is that a histogram is only used to plot the frequency of score occurrences in a continuous data set that has been divided into classes, called bins.  bar charts, on the other hand, can be used for a great deal of other types ofvariables  including  ordinal  andnominal  data sets.