Respuesta :
The interval of filled bags is at confidence interval of 95%.
At 95% confidence interval, Z=1.96 (from Z tables).
But,
Z= (x-mean)/sd => 1.96 = (x-450)/20 => x (upper limit)= 20*1.96+450489 bags
Lower limit or minimum number bags to avoid replace= 450-1.96*20 =411 bags
At 95% confidence interval, Z=1.96 (from Z tables).
But,
Z= (x-mean)/sd => 1.96 = (x-450)/20 => x (upper limit)= 20*1.96+450489 bags
Lower limit or minimum number bags to avoid replace= 450-1.96*20 =411 bags