The daily sales (in dozens of pastries) of a bakery over 10 days are given in the table

MATHEMATICS · Single correct · A Level · Mathematics · Data presentation and interpretation · Data presentation and interpretation

Problem

The daily sales (in dozens of pastries) of a bakery over 10 days are given in the table. Class mark

(x)

: 10 20 30 40 Frequency

(f)

: 2 3 4 1 What is the variance of the sales (in dozens

^{2}

)? (a) 85 (b) 84 (c) 93.3 (d) 58.4