The following table summarises the number of tomatoes produced by the plants in the plots on a farm.

No. tomatoes	$20-29$	$30-49$	$50-79$	$80-100$
No. plots $\left(f\right)$	$329$	$413$	$704$	$258$

Calculate an estimate of the mean number of tomatoes produced by these plots.

The following table summarises the number of tomatoes produced by the plants in the plots on a farm.

The tomatoes are weighed accurately and their mean mass is found to be $156.50$ grams. At market they are sold for $\$3.20$ per kilogram and the total revenue is $\$50350.$ Find the actual mean number of tomatoes produced per plot.

The following table summarises the number of tomatoes produced by the plants in the plots on a farm.

The tomatoes are weighed accurately and their mean mass is found to be $\$156.50$ grams. At market they are sold for $\$3.20$ per kilogram and the total revenue is $\$50350$. Why could be the mean inaccurate?

Twenty boys and girls were each asked how many aunts and uncles they have. The entry $4/5$ in the following table, for example, shows that $4$ boys and $5$ girls each have $3$ aunts and $2$ uncles.

Find the mean number of uncles that the boys have.

Twenty boys and girls were each asked how many aunts and uncles they have. The entry $4/5$ in the following table, for example, shows that $4$ boys and $5$ girls each have $3$ aunts and $2$ uncles.

For the boys and girls together, calculate the mean number of aunts.

Twenty boys and girls were each asked how many aunts and uncles they have. The entry $4/5$ in the following table, for example, shows that $4$ boys and $5$ girls each have $3$ aunts and $2$ uncles.

For the boys and girls together, calculate the mean number of aunts and uncles.

Twenty boys and girls were each asked how many aunts and uncles they have. The entry $4/5$ in the following table, for example, shows that $4$ boys and $5$ girls each have $3$ aunts and $2$ uncles.

Suggest an alternative way of presenting the data so that the calculations in parts $a$ and $b$ would be simpler to make.

A calculated estimate of the mean capacity of $120$ refrigerators stored at a warehouse is $348$ litres. The capacities are given in the following table.

A delivery of $n$ new refrigerators, all with capacities between $200$ and $320$ litres arrives at the warehouse. This causes the mean capacity to decrease by $8$ litres. Find the value of $n$ and state what assumptions you are making in your calculations.

A carpet fitter is employed to fit carpet in each of the $72$ guest bedrooms at a new hotel. The following table shows how many rooms were completed during the first $10$ days of work.

Based on these figures, estimate how many more days it will take to finish the job. What assumptions are you making in your calculations?