Answer: 601
Step-by-step explanation:
The formula to find the minimum sample size(n) , if the prior population proportion is unknown:
, where E = margin of error ,
= critical z-value for confidence level c.
Given : E = 0.04
Z-value for 95% confidence = 1.96
So, the minimum sample size required = 

Hence, the minimum sample size required = 601
5 dollars because she paid 30 for the meal
Answer:
16
since it's the least that can be divided by both
Answer:
0.24315
Step-by-step explanation:
Using the z score formula to solve this question
z = (x - μ) / σ,
Such that:
x = raw score
μ = population mean
σ = population standard deviation.
From the question:
x = 3000
μ = 3550
σ = 870
z = (3000 - 3550) / 870
z = -550/870
z = -0.6962
Using the z score table as well as probability calculator(as requested in the question to find the z score)
The probability of having less than 3000 is obtained as:
P(x<3000) = 0.24315