Analysis of Phone Dataset
Part 1: Data Analysis (mostly handwritten —a maximum of 8 pages);
Part 2: A reply to Harry Kane’s questions in the form of a memorandum (maximum of two pages).
As was the case in Assignment 1, you are playing the role of Virat Kohli,an analyst at an electronics and communication magazine. Harry Kane,one of the senior editors at the magazine, has written to you again regarding the phone dataset. His memorandum is reproduced below.
For Attention: Virat Kohli 2/5/2017
From: Harry Kane
Regarding: Further analysis of Phone dataset
Thank you for your earlier response. I also need the following information.
1. Please provide me with a 90% confidence interval for:
a. The mean monthly bill for ALL users?
b. The proportion of ALL users who are on a post-paid plan?
2. We wrote previously that, on average, phone users spend more than $61.50 on their monthly bill. Please check if this is still the case (at 5% significance).
3. We also wrote previously that less than 65% of phone users are on a post-paid plan. Please verify that this is still the case (at 5% significance).
4. Please check if there is a difference in the mean monthly bill between ALL male and ALL female phone users (at 90% confidence).
5. The dataset is a sample of 150 users. What sample size would be needed in order to be able to estimate:
a. The mean monthly bill for ALL phone users to within $2.50, with 90% confidence?
b. The proportion of ALL phone users who are on a post-paid plan to within 4%, with 90% confidence?