Question

the mean sugar content in breakfast cereal is manufactured to be 11g of sugar per serving- a serving is defined to be 30g of cereal. the manufacturing process is controlled such that the standard deviation is only 0.8 g per serving. after an overhaul of the equipment, the sugar content is checked using a sample of 35 measurements which are averaged to find a mean sugar content of 10.7 g per serving. is there strong evidence that the true mean sugar content has changed due to equipment servicing?

we have to find value of P ( proportion ) or Z ?

Answer 1