You measured the average number of litres of water used per day at 25 random houses over 30 day interval. The mean water use per house is 711.0 litres per day & the 95% confidence interval ranges from 682.8 to 739.2 L per day. the water supply can provide an average of 640 L of water a day to each house. Use the 95% confidence interval to test the claim that water supply differs form water use in this town.

i) state the null and alternate hypotheses of the statistical test

ii) what does the 95% interval mean? or how do you interpret the 95% confidence interval?

iii) based on the 95% confidence interval and threshold level of significance (alpha) of 0.05 what should you conclude? Justify your answer.

iv) list 4 assumptions that must be met in order for the resulting 95% confidence interval to be accurate