Please just give me the Null and Alternate Hypothesis for the following:

In this form:

Ho:

H1:

1. A manufacturer of televisions claims that the average life of its screens is more than 8 years. a study is conducted on 35 randomly selected televisions from the manufacturer. Test the claim.

2. A student group is interested in studying whether less than 20% of college students take public transportation. A random sample of 420 students was taken to test the group's claim.

3. Measurements of left handed and right handed gripping strengths of 40 left-handed persons are recorded. You wish to test whether left-handed persons on average have greater gripping strength in their left hands and are willing to assume that gripping strengths are normally distributed.

4. A survey to help understand emotions showed 22 of 70 subjects under 18 years of age expressed fear of meeting people, while 23 of 90 subjects 18 years and older expressed the same fear. You wish to study if there is a difference in the two groups over a fear of meeting people.