8. A nutritionist created a 95% confidence interval to estimate the average amount of sugar (grams) consumed by an individual per day (18, 63.8) grams. What is the value of the width of this confidence interval? Please give your answer correctly rounded to two decimal places and do NOT include units in your answer.

9. The production manager at a textile mill, believes that a new machine, producing cloth, is not working according to the company's specifications. The company requires that the cloth should have a mean breaking strength of 35 Kg. A sample of 80 pieces of cloth reveals a sample mean breaking strength of 40.3 Kg and a standard deviation of 2.9 Kg. If the manager wants to do a hypothesis test to her belief, what value of the mean would be used in the null and the alternative hypotheses?

10. The owner of a company wanted to investigate the relationship between weekly revenue ($000) and weekly advertising expenditure ($). She took a random sample of different weeks and recorded the corresponding revenue and advertising expenditure for each week selected. Excel was then used to create the following regression output:

SUMMARY OUTPUT
Regression Statistics
Multiple R	0.60000
R Square	0.36000
Observations	13

	Coefficients	Standard Error
Intercept	21.83293	0.50766
Advertising Expenditure	8.40292	0.03546

For each extra dollar spent on advertising per week, how much is weekly revenue estimated to increase by?

Please give your answer correctly rounded to two decimal places.