sensitivity and specificity

[Gamewizard]

Hi all

 

I have a question which I am confused about I really dont know how to work it out.

 

A total of 981 patients were tested. 10% of patients had a positive result of which 70 were actual true positives. Out of the population reporting a negative result, 95% were actually true negatives.

 

Calculate the sensitivity and specificity.

 

Ok i have the formula for calculating sensivity and specificity and know how to calculate them but, i dont know how to get the numbers of true positives, false positives, false negatives and true negatives from this kind of data.

 

Can anyone help please thank you .

[Mr Skeptic]

Well you could start by replacing the percentages with number of patients. And show your work, so we can help you better. You should be able to get 4 numbers, and if you think about it it should be fairly easy to see which type of result they are.

[Gamewizard]

I have got it now thanks anyway