Work out the spread

Exercise and reference answers

Questions

1. Hint

   mean = A + Σfd/N

   Answer

   204.167

   Question

   N = 36, Σfd = −750, A = 225. Find the mean to 3 d.p.

2. Hint

   straight division

   Answer

   5486.111

   Question

   Σfd² = 197500, N = 36. Find Σfd²/N to 3 d.p.

3. Hint

   N ÷ 4

   Answer

   9

   Question

   N = 36. What is the position of the first quartile?

Instructions

Use the totals given and key in the answer.