Proposition D, which is on the ballot in District of Columbia in November 2021 elections, aims to provide affordable housing in certain neighborhoods of DC for low income residents. You are working for the campaign to support Proposition D and the campaign is planning to hold a fund raising event. The capacity of the event is 300 guests and the event is full. During the event, the guests will be asked to make donations. In the past, in similar events, the average donation per guest has been $1,600 with a standard deviation $900, and you expect these to be the same for this event as well. Your target for this event is to raise at least $500,000.

(a) Give a precise Excel expression with correct numerical inputs that would calculate the probability you will exceed your target fund raising level in this event.

(b)\Provide the 90 % Confidence Interval (centered around the mean) for the total amount you will raise for this event.