Paper 6 May/June 2011 MATHEMATICS (9709/62) A Levels
لطفا برای اطمینان از عملکرد و تجربه بهتر از مرورگرهای مدرن و به روز مانند کروم یا فایرفاکس استفاده کنید.

The weights in grams of a number of stones, measured correct to the nearest gram, are represented in the following table.
A histogram is drawn with a scale of 1 cm to 1 unit on the vertical axis, which represents frequency density. The 1 − 10 rectangle has height 3 cm.
a) Calculate the value of x and the height of the 51 − 70 rectangle.
b) Calculate an estimate of the mean weight of the stones.