Question 1193316
Median :
M = value of {{{(n+1)/2}}} th observation

= value of {{{(18/2)}}} th observation

= value of 9th observation

From the column of cumulative frequency cf, we find that the 9th observation is 3.

Hence, the median of the data is 3.

Mode :
the frequency of observation 5 is maximum (5)

∴Z=5

Part b:

Median :
M = value of {{{(n+1)/2}}} th observation

= value of {{{ 13/2}}} th observation

= value of 6.5th observation

From the column of cumulative frequency cf, we find that the 6.5th observation is 55.

Mode :
the frequency of observation 55 is maximum (4)

∴Z=55