A firm must decide between two different suppliers of lightbulbs. Management has decided to order from supplier A unless it can be proven that the mean lifetime of lightbulbs from supplier Bis...

Extracted text: A firm must decide between two different suppliers of lightbulbs. Management has decided to order from supplier A unless it can be proven that the mean lifetime of lightbulbs from supplier Bis superior. A test of 28 lightbulbs from A and 32 lightbulbs from B yielded the following data as to the number of hours of use given by each lightbulb: a 121 76 88 103 96 89 100 112 105 101 92 98 87 75 111 118 121 96 93 |82 105 78 84 96 103 119 85 84 b 127 133 87 91 81 122 115 | 107 109 89 82 90 81 104 | 109 110 106 85 93 90 100 122 117 109 98 94 103 107 101 99 112 90 Is there a significant difference between the two suppliers? Explain.