hey i am stuck on this practise test this is the questionsi have no idea

a)how do I Explain numerical, ordinal, nominal, cross sectional and time series data and provide two examples of each data type.

b)What are5 points the researcher needs to consider when designing a questionnaire.

c)A small corporation employs 100 employees which include some high-ranking management people who earn very high salaries. What is the most appropriate measure of central location to characterize a typical employees' salary? Why?

d)whatsthe difference between Type I error and Type II error.

this is all the information provided to me