Both crops are individual series of 10 values; sorting each and computing the five measures lets us compare their variability. …

WHEAT — sorted: 9, 10, 10, 12, 15, 16, 18, 19, 21, 25 (n = 10, sum = 155, mean = 15.5, median = (15+16)/2 = 15.5).

• (i) Range $= 25 - 9 = 16$.
• (ii) Q.D. — $Q_1$ is the $\dfrac{n+1}{4} = 2.75\text{th}$ value $= 10$; $Q_3$ is the $\dfrac{3(n+1)}{4} = 8.25\text{th}$ value $= 19 + 0.25(21-19) = 19.5$. $Q.D. = \dfrac{19.5 - 10}{2} = 4.75$.
• (iii) M.D. about mean (15.5) — $\sum |d| = 3.5+5.5+0.5+3.5+5.5+0.5+2.5+6.5+9.5+5.5 = 43$; $M.D. = \dfrac{43}{10} = 4.3$.
• (iv) M.D. about median (15.5) — the median equals the mean here, so $M.D. = \dfrac{43}{10} = 4.3$.
• (v) S.D. — $\sum (X-\bar{X})^2 = 254.5$; $\sigma = \sqrt{\dfrac{254.5}{10}} = \sqrt{25.45} = 5.04$.

RICE — sorted: 12, 12, 12, 15, 18, 18, 22, 23, 29, 34 (n = 10, sum = 195, mean = 19.5, median = (18+18)/2 = 18).

• (i) Range $= 34 - 12 = 22$.
• (ii) Q.D. — $Q_1$ is the 2.75th value $= 12$; $Q_3$ is the 8.25th value $= 23 + 0.25(29-23) = 24.5$. $Q.D. = \dfrac{24.5 - 12}{2} = 6.25$.
• (iii) M.D. about mean (19.5) — $\sum |d| = 2.5+9.5+7.5+3.5+1.5+4.5+7.5+14.5+1.5+7.5 = 60$; $M.D. = \dfrac{60}{10} = 6.0$.
• (iv) M.D. about median (18) — $\sum |d| = 4+11+6+5+0+3+6+16+0+6 = 57$; $M.D. = \dfrac{57}{10} = 5.7$.
• (v) S.D. — $\sum (X-\bar{X})^2 = 512.5$; $\sigma = \sqrt{\dfrac{512.5}{10}} = \sqrt{51.25} = 7.16$. …