Answer: 601
Explanation:
When the prior estimate of the population proportion is unavailable , then the formula to find the sample size is given by :-
![n= 0.25((z^*)/(E))^2](https://img.qammunity.org/2020/formulas/mathematics/college/g4cc2iuz5tiyjgqatgome1585f2mihmmy9.png)
, where E = margin of error
and z* = Critical z-value associated with the confidence level.
As per given , we have
The prior percentage of full-time college students who earn a bachelor's degree in four years or less is not given.
E= 0.04
We know that the critical value for 95% confidence level = z*= 1.960
Then , the required sample size is given by :-
![n= 0.25((1.960)/(0.04))^2](https://img.qammunity.org/2020/formulas/mathematics/college/xr2laz1ju8r3sece929zzwmn65lenk32so.png)
![n= 0.25(49)^2](https://img.qammunity.org/2020/formulas/mathematics/college/dzn4humcyp0ux7oz1i2n3l8sl0t4rpk56i.png)
Hence, the required sample size is 601.