An apple grower is trying to produce larger fruit by using a new fertilizer. The usual fertilizer produces fruit with a mean diameter of 8.7 cm. Two new fertilizer brands are under consideration, with the following experimental results:

Question

An apple grower is trying to produce larger fruit by using a new fertilizer.  The usual fertilizer produces fruit with a mean diameter of 8.7 cm.  Two new fertilizer brands are under consideration, with the following experimental results:
	BRAND A:  n = 10, mean = 9.5 cm, s = 4 cm	BRAND B:  n = 10, mean = 10.8 cm, s = 3 cm
Calculate the 98% confidence interval for the true difference between the means of the two brands.  	 [5]
Do you think that Brand B is significantly better than Brand A?