A normal distruibution of 640 observations has a mean of 1800 cm and a standard deviation of 90 cm.
A) Draw a representative diagram for the distribution.
B) Determine the proportion of observations (i)between 1620 cm and 1980 cm (ii) between 1710 cm and 2070 cm (iii)above 1890 cm (iv) below 2070 cm.
C) Determine the number of observations (i)between 1710 cm and 1890 cm; (ii)between 1530 cm and 1620 cm;(iii)below 1890 cm; (iv)above 2070 cm