Can you please help me with this question? Thank you so much.

A large publishing house recently conducted a survey to assess the reading habits of teenagers. The company publishes four magazines specifically tailored to suit the interests of teenagers. Management hypothesized that there were no differences in the references for the magazines. A sample of 1600 teenagers indicated the following preferences for the four magazines:

Magazine Frequency of Preference

Magazine 1 350

Magazine 2 500

Magazine 3 450

Magazine 4 300

Total 1600

Management needs your expertise to determine whether there are differences in teenager preferences for the magazines.

a. State in plain English (not using equations!) your null and alternate hypotheses.

b. How many degrees of freedom are there?

c. What is the calculated chi-squared value? Show your calculations. (Use a tabled chi-squared of 7.81, for 5% significance and 3 degrees of freedom.)

d. What can you conclude about the preferences of teenagers for these magazines?