1. The chart shows the results of a research investigation that assesses the accuracy of Method X and Method Y in diagnosing a condition found in pigeons. 

Q1. 47 pigeons were incorrectly identified as ‘positive’ by Method X, when they did not actually have the condition. How many pigeons were tested in the investigation of Method X in total?

2. Q2. For every 10 000 pigeons Method Y identifies as being likely to have the condition, how many pigeons would you expect to actually have the condition?

3. Q3. The cost of wrongly identifying a pigeon as have a negative diagnosis is £760 and wrongly identifying the pigeon as having a positive diagnosis is £220. Around 1600 pigeons per year get positive diagnoses and 310 receive negative diagnoses. What is the approximate difference in the cost of using Method X and Y?