Statistical dummy asks for help


I have no idea how to solve those questions. If there is anybody, who knows the answers, I'd really appreciate if you help me.

1. One-*‐fourth of 300 person in a large city stated that they are opposed to a certain political issue favored by the mayor. Calculate a 99% confidence interval for the fraction of people of individuals opposed to this issue. Explain your answer.

2. Twenty percent of the participants of the selected course belong to a club; fourty percent work part time. Five percent of the participants work part time and belong to a club. Draw a Venn diagram showing the relationships.Find the probability that the participant belongs to a club or works part time.

3. A researcher wishes to estimate the number of households with two cars. How large a sample is needed in order
to be 98% confident that the sample proportion will not differ from the true proportion by more than 5%? A previous study indicates that the proportion of households with two cars is 20%.

4. Sales promotions that are used by manufacturers to push the manufacturer's products are called trade promotions.
A survey of 250 manufacturers conducted by a marketing consulting firm, found that 91 % of the manufacturers believe their spending for trade promotions is inefficient. Is this sufficient evidence at α = 0.02 to reject a previous claim by the American Marketing Association that no more than half of all manufacturers are dissatisfied
with their trade promotion spending?