The table shows information about the mass, m grams, of each of 120 letters.11Mass (m grams)21253143FrequencyCalculate an estimate of the mean mass.(a)................................................... g [4]9Iraj draws a histogram to show this information.He makes the height of the first bar 17.2 cm.Calculate the height of each of the remaining bars.(b)height of bar for ................................................... cmheight of bar for ................................................... cmheight of bar for ................................................... cm [3]

The question seems to be incomplete. However, I can guide you on how to approach it based on the information provided.

(a) To calculate an estimate of the mean mass, you need to multiply each mass by its frequency, sum up these products, and then divide by the total frequency (which is the total number of letters, 120 in this case).

The formula is: Mean = Σ(mass * frequency) / total frequency

The mass and frequency data seem to be missing from your question, so I can't provide a numerical answer.

(b) The height of the bars in a histogram represents the frequency density, not the frequency. Frequency density is calculated by dividing the frequency by the class width (the range of values in each bar).

The formula is: Frequency Density = Frequency / Class Width

Again, without the specific data for each bar (the frequency and class width), I can't provide a numerical answer.

Please provide the complete data so I can help you further.