Common ratio, r = 2
Let a be the first term of the G.P.
∴ a8 = ar 8–1 = ar7
⇒ ar7 = 192
a(2) 7 = 192
a(2) 7 = (2)6 (3)
⇒a = (2)6 × \(\frac{3}{(2)}7=\frac{3}{2}\)
∴ a12 = ar12 - 1 = \((\frac{3}{2})\)(2)11 = (3)(2)10 = 3072
Find the mean and variance for the following frequency distribution.
Classes | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 |
Frequencies | 5 | 8 | 15 | 16 | 6 |