In: Statistics and Probability
If the absenteeism rates for a school district rise above 10%, the state reduces its aid to the school district. Stermerville independent school district takes a sample of five schools within the district and finds the following absenteeism rates:5.4%,8.6%,4.1%,8.9%, and 7.8%. What is your best estimate of the absenteeism rate in Stermerville? Is it likely that the absenteeism rate is greater than 10%?
Ho : µ = 10
Ha : µ > 10
Level of Significance , α =
0.05
sample std dev , s = √(Σ(X- x̅ )²/(n-1) )
= 2.1078
Sample Size , n = 5
Sample Mean, x̅ = ΣX/n = 6.96
so, best estimate of the absenteeism rate in
Stermerville = 6.96%
degree of freedom= DF=n-1=
4
Standard Error , SE = s/√n =
0.9427
t-test statistic= (x̅ - µ )/SE =
-3.22
p-Value = 0.9839 [Excel
function =NORMSDIST(-z)
Conclusion: p-value>α, Do not reject null
hypothesis
so, yes, it is likely that the absenteeism rate is greater than 10%?