I am trying to find an assignment of STAT 555 that can help me answer some questions. One of them is: How can I interpretate result between to groups having the media, mode, etc.?

Exercise 1 Una encuesta de 225 trabajadores en Los Angeles y 260 trabajadores en Nueva York solicito a cada uno que informara la cantidad promedio de tiempo dedicado al viaje al trabajo.

Exercise 2- Determine the sample size nivel de confianza = 95%, poblacion = 5,280, margen de error= 5% i know the result is 5,273 but how I get to that answer.