Please explain the theory involved first, then step by step, detailed explanations ,with good presentations, answer and explanations to all parts please, please leave the question if you cant , as it would hurt your profile, thank you!

Write the null and alternative hypotheses (in symbols and then words] for each of the following situations. a. New York is known as "the city that never sleeps\". A random sample of 25 New Yorkers were asked how much sleep they get per night. Do these data provide convincing evidence that New Yorkers on average sleep less than 8 hours a night? b. An employer is worried about the effect of the World Cup on employee productivity. The employer estimates that on a regular business day, employees normally spend on average 15 minutes checking personal email, making personal phone calls, browsing the internet, and so on. To examine whether the World Cup increases the amount of time spent on personal activities at work, the employer collects time-use data on a random sample of employees during the World Cup. The employer wishes to determine whether these data provide convincing evidence that the World Cup decreases employee productivity. c. It is believed that near-sightedness affects about 8% of all children. A random sample of children is collected to determine whether this belief about the proportion of children who are near-sighted is accurate