Question

Coal-fired power plants used in the electrical industry have gained public attention because of the environmental problems associated with solid wastes generated by large-scale combustion. A study was conducted to measure the EC50 (Effective Concentration, in mg/L, that decreases 50% of the light in a luminescence bioassay) at four different locations. The experimental data found:

Largest value = 73,350    Smallest value = 73,300    

Sample mean = 73,325 s = 20.81666

Find the values of the 2-middle sample observations. (Do not use successive guessing).

Answer 1

MTB > let k1 = (4*73325) - (73350 +73300)
MTB > print k1

Data Display

K1    146650

MTB > let k2 = (3*(20.81666**2))-((73350-73325)**2)-((73300-73325)**2)
MTB > print k2

Data Display

K2    50.0000

MTB > let k3 = k2 + (2*73325*k1) - (2*(73325**2))
MTB > print k3

Data Display

K3    10753111300

MTB > let k4 = (k1**2)-k3
MTB > let k5 =k4/2
MTB > print k5

Data Display

K5    5376555600

MTB > let k6 = sqrt(k3 - (2*k5))
MTB > print k6

Data Display

K6    10.0000

MTB > let k7 = (k1+ k6)/2
MTB > let k8 = (k1-k6)/2
MTB > print k7 k8

Data Display

K7    73330.0    ......x1
K8    73320.0    ......x2