course: Complexity Theory and data structures

please answer the shown questions with an explanation for each one .

here is the excel sheet of the question, please note it contains three columns (the first column is the first name, the second column is the last name and the third column is the mark) it has also 1048576 rows. here is a part of the excel please let me know if any other is needed.

I will vote up for the correct answer and write a good review for who answers correct.

A university wants to build a system that processes a data set of student marks. The data set consists of student records were each record has the following structure: - Student first name - Student last name - Student mark The system need to execute the following tasks 1. Compute the average of the marks using equation markavg=1nmarki 2. Compute the standard deviation of the marks markstd=n1n(markimarkavg)2 3. Find all the students that got marks higher than markhigh where Answer the following questions a) What is the time complexity of the first 2 steps (computing mean and the standard deviation)? explain your answer. b) For step 3 (finding all students with high marks), Nadia suggested to first sort all the students by their marks in descending order (using merge sort) then go from the biggest mark until we reach a mark below mark wain . What is the time complexity of this approach? Explain your answer. c) Can you find a more efficiently approach to achieve step 3? Explain and analyze the time complexity of your