if the sum of five number in gp is 155 and sum of last five terms is 39680 . first term is 5 andast term is 20480. find number of terms​

I’m stuck on this equation, anyone got the answer?

Unaware that 35% of the 10000 voters in his constituency support him, a politician decides to estimate his political strength. a sample of 200 voters shows that 40% support him. a. what is the population? b. what is the parameter of interest? state its value c. what is the statistics of the interest? state its value d. compare your answers in (b) and (c) is it surprising they are different? if the politician were to sample another 200 voters, which of the two numbers would most likely change? explain

Asinusoidal function whose frequency is 1/6pi