A researcher wishes to estimate, with 95% confidence, the percentage

1. A researcher wishes to estimate, with 95% confidence, the percentage of adults who support abolishing the penny. His estimate must be accurate within 5% of the true proportion. Find the minimum sample size needed, using a prior study that found that 34% of the respondents said they support abolishing the penny. Round to the nearest whole number as needed. n=? What is the minimum sample size needed assuming that no prior information is available? n=? 

2. find the indicated probability using the standard normal distribution.
p(-3.04<z<3.04)

3. find the margin of error for the given values of c,s, and n
c=0.90, s=3.5, n=29

4. find the critical value of Tc for the confidence level c=0.95 and sample size n=29
Tc=

5. find the margin of error for the given values of c,s, and n
c=0.90, s=2.8, n=81