(i) The back-to-back stem-and-leaf diagram is constructed as follows:

Key: \( 5 \mid 8 \mid 4 \) means \( 0.85 \) m for flat screen.

(ii) To find the median of the conventional TVs, order the data: 0.65, 0.67, 0.69, 0.71, 0.74, 0.75, 0.77, 0.85, 0.86. The median is the middle value, 0.74.

The interquartile range (IQR) is calculated as the difference between the upper quartile (UQ) and the lower quartile (LQ). LQ = 0.68, UQ = 0.81, so IQR = 0.81 - 0.68 = 0.13.

(iii) For the flat screen TVs, calculate the mean:

Mean = \(\frac{0.85 + 0.94 + 0.91 + 0.96 + 1.04 + 0.89 + 1.07 + 0.92 + 0.76}{9} = 0.927\).

Calculate the standard deviation (SD):

SD = \(\sqrt{\frac{(0.85-0.927)^2 + (0.94-0.927)^2 + (0.91-0.927)^2 + (0.96-0.927)^2 + (1.04-0.927)^2 + (0.89-0.927)^2 + (1.07-0.927)^2 + (0.92-0.927)^2 + (0.76-0.927)^2}{9}}\)\( \approx 0.0882\).