Hello,

I have the following question which I'm really struggling with.

The data come from the records of an estate agent and relate to sales of private houses. A random sample of sales was taken from the records and the following table gives the frequency of each type of sale.

If two of the properties are chosen at random, with replacement, the probability that they have 7 bedrooms between them is (3 d.p.):

The correct answer is **0.093**.

I've calculated

p(3) = 0.284

p(4) = 0.165

I assume since it has to be 8 bedroom, we're looking for the probability of a 3 bed plus a 4 bed?

I tried calculating it by using a variety of different methods:

- p(3)*p(4)=0.0466

- (p(3)*p(4))/p(4)=0.283

- (p(3)*p(4))/p(3)=0.164

- p(3)+p(4)=0.447

I really cannot get my head around this. I've not been able to come anywhere near the correct answer, and I'm really struggling.

I'd be grateful if anyone could assist (even if you're just pointing me in the right direction)

Thanks in advance.