16, 18, 23, 25, 26, 34, 37, 37, 40, 41, 46
37 is the upper quartile value
Alex = 6x
Peter = x
6x = x + 50
5x = 50
x = 10
Alex = £60
Peter = £10
together = £70
It takes 45 seconds. the easiest way to do these is to use a graphic calculator and replace the variables with x and y, for example, this equation would become -5x^2+30x, and if you don't have access to a graphing calculator, you can always use desmos online.
Answer:

For the interpretation we consider a value for d small is is between 0-0.2, medium if is between 0.2-0.8 and large if is higher than 0.8.
And on this case 1.713>0.8 so we have a large effect size
This value of d=1.713 are telling to us that the two groups differ by 1.713 standard deviation and we will have a significant difference between the two means.
Step-by-step explanation:
Previous concepts
The Effect size is a "quantitative measure of the magnitude of the experimenter effect. "
The Cohen's d effect size is given by the following formula:

Solution to the problem
And for this case we can assume:
the mean for females
the mean for males
represent the deviations for both groups
And if we replace we got:

For the interpretation we consider a value for d small is is between 0-0.2, medium if is between 0.2-0.8 and large if is higher than 0.8.
And on this case 1.713>0.8 so we have a large effect size
This value of d=1.713 are telling to us that the two groups differ by 1.713 standard deviation and we will have a significant difference between the two means.
1,995,000
The number after the thousands place is 2, which is less than 5 so the thousands place is rounded to 5,000 instead of 6,000.