How can you find a representative value for each interval? Should each interval be given equal weight when calculating the mean?

To find a representative value for each interval, you can use the midpoint of each interval. The midpoint is calculated by adding the lower and upper limits of the interval and dividing by 2. This gives you a single value that represents the entire interval.

As for the second part of your question, it depends on the context. If each interval represents the same number of data points, then yes, each interval should be given equal weight when calculating the mean. However, if the intervals represent different numbers of data points, then the intervals should be weighted according to the number of data points they represent. This is because the mean is influenced by every value in the data set, so intervals with more data points should have a greater influence on the mean.