Let's analyze the question and address it step by step.

Problem Breakdown:

• Given:
  • Previous mean time $\mu = 20.1$ minutes.
  • Sample size $n = 103$.
  • Sample mean $\bar{x} = 22.1$ minutes.
  • Population standard deviation $\sigma = 7$.
  • Significance level $\alpha = 0.05$.
• Goal: Determine if the mean time spent browsing Netflix has changed (two-tailed test).

Part (a) Null and Alternate Hypotheses

• The null hypothesis ($H_0$): There is no change in the mean time spent browsing Netflix. $H_0: \mu = 20.1$
• The alternate hypothesis ($H_1$): The mean time spent browsing Netflix has changed. $H_1: \mu \neq 20.1$

This is a two-tailed test since the question is testing whether the mean has changed, rather than specifically increased or decreased.

Let me know if you need further assistance or details on hypothesis testing steps.

Related Questions:

1. What is the next step after stating the hypotheses in hypothesis testing?
2. How do we calculate the test statistic for this scenario?
3. What does the critical value method involve, and how does it relate to the significance level?
4. How can we interpret the results to decide whether to reject $H_0$?
5. What is the role of the sample size $n$ in hypothesis testing?

Tip:

Always start hypothesis testing by clearly defining the null and alternate hypotheses and ensure they align with the problem's question.