A & B two sets of packaging machines, at the same time packaging quality of 500 kilograms of goods
(3) large variance, indicating that this group of data volatility, variance is small, volatility is relatively stableAnswer: (1) a = x (501+500+503+506+504+506+500+498+497+495), 10=501,B = x (503+504+502+498+499+501+505+497+502+499), 10=501;(2) S2, =1/n[(501-501) 2+ (500-501) 2+... + (495-501) 2]=12.6,S2 B, =1/n[(503-501) 2+ (504-501) 2+... + (499-501) 2]=6.4;(3) a b > S2 dreams S2,The quality of R B packaging machine 10 bags of sweets is relatively stable.Comments on the subject, mainly on the average number, variance calculation, and their significance, the correct memory formula is the key to solving problems
(1) calculate the average of two samples;(2) the variance of two samples was calculated;(3) which packaging machine is more stable in packing quality?(1) according to the average, the number divided by the sum of each group;
10 bags were randomly extracted from each of them, and the actual quality was measured as follows: (unit G)A: 501500503506504506, 500498497495B: 503504502498499501, 505497502499
