Respuesta :
Solution :
   x          [tex]$(x-\overline x)$[/tex]              [tex]$(x-\overline x)^2$[/tex]
45860 Â Â Â Â Â Â -1742.8571 Â Â Â Â Â Â Â Â 3037551.0204
38860 Â Â Â Â Â Â -8742.8571 Â Â Â Â Â Â Â Â 76437551.0204
64820 Â Â Â Â Â Â Â 17217.1429 Â Â Â Â Â Â Â Â 296430008.1633
63480 Â Â Â Â Â Â 15877.1429 Â Â Â Â Â Â Â Â 252083665.3061
36710 Â Â Â Â Â Â Â -10892.8571 Â Â Â Â Â Â Â 118654336.7347
50410 Â Â Â Â Â Â 2807.1429 Â Â Â Â Â Â Â Â 7880051.0204
33080 Â Â Â Â Â Â -14522.8571 Â Â Â Â Â Â 210913379.5918 Â Â
333220 Â Â Â Â Â 0.0000 Â Â Â Â Â Â Â Â Â Â Â Â 965436542.8571
Sample size, n = 7
Mean = [tex]$\frac{\sum x}{n}=\frac{333220}{7}$[/tex]
          = 47602.8571
Variance = [tex]$\frac{(\sum (x- \overline x))^2}{(n-1)}=\frac{965436542.8571}{7-1}$[/tex]
                    = 160906090
Standard deviation = [tex]$\sqrt{Variance} = \sqrt{160906090}$[/tex]
                           = 12684.876
a). df = n - 1
    = 7 - 1
    = 6
Level of significance, α = 0.02
Critical, [tex]$t_c = 3.143$[/tex]
b). Sample mean, [tex]$\overline x = 47602.8571$[/tex]
  Sample standard deviation, s = 12684.876
Sample size, n = 7
c). 98% confidence interval = [tex]$\overline x \pm t_c \times \frac{s}{\sqrt n}$[/tex]
                       [tex]$=47602.8571 \pm 3.143 \times \frac{12684.876}{\sqrt 7}$[/tex]
                       [tex]$=(32533.96,62671.76)$[/tex]
