We can calculate the margin of error, ME, using the following formula:

where, p is the proportion, n the sample size, and z is the z-score,
for this example:
z = 1.96 because the confidence level is 95%
p = 28/147
n = 147
let's replace and solve
![ME=1.96\cdot\sqrt[]{((28)/(147)\cdot(1-(28)/(147)))/(147)}](https://img.qammunity.org/2023/formulas/mathematics/college/8v3hvi7x9fd077p7heya39tt3qftff64h2.png)
solving this, we obtain

which is the same as:
ME = 6.3%