The garage records show that in 1997 50 exhaust systems, 400 batteries, and 1000 tyres were purchased. Use these figures and the price figures from Example 4.9 to produce a Laspeyre price index to compare the prices of 2000 to those of 1997.

q0pc

q0p0

× 100 =

(50 × 156) + (400 × 35) + (32 × 1000)

(50 × 125) + (400 × 25) + (28 × 1000)

× 100

=

53 800 44 250

× 100

= 121.6 to one decimal place This suggests that the prices have increased by 21.6 per cent between 1997 and 2000.