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%?