Answer:
a) SE = 25
b) MOE = 41
c) CI = 1951 ; 2049
Step-by-step explanation:
Normal distribution
Population mean unknown
Population standard deviation σ = 350 Kwh
a) The standard error of the mean SE is
SE = σ/√
SE = 350 /√196
SE = 350/14
SE = 25
b) If confidence nterval is 95% or 0,95 then
α = 0,05
And from z table we get z(c) = 1,64
MOE = z(c) * SE
MOE = 1,64 * 350/√196
SE = 1,64 * (350)/14
SE = 41
MOE = And from z tabl we get z(c) = 1,64
MOE = 1,64 * 350/√196
MOE = 1,64 * (350)/14
MOE = 1,64 * 25
MOE = 41
c) The confidence interval is:
Z = 2000
α = 1- 0,95
α = 0,05 ⇒ α/2 = 0,025
CI = Z - z(α/2) * σ/√n ; Z + z(α/2) * σ/√n
z(α/2) from z-table is: z(0,025) = 1,96
CI = 2000 - 1,96* 350/√196 ; 2000 + 1,96* 350/√196
CI = 2000 - 1,96*25 ; 2000 + 1,96*25
CI = 2000 - 49 ; 2000 + 49
CI = 1951 ; 2049
