Hello, I hope you can help me with this question. Mathematics is simply not my better subject. Thank you!

The question:

What is the minimal sample size needed for a 95% confidence interval to have a maximal margin of error of0.1in the following scenarios? (For each answer, enter a number. Round your answers up the nearest whole number.)

(a)a preliminary estimate forpis0.34

(b)there is no preliminary estimate forp