Answer:
We conclude that children in district are brighter, on average, than the general population.
Step-by-step explanation:
We are given the following data set:
105, 109, 115, 112, 124, 115, 103, 110, 125, 99
Formula:
 
  
where  are data points,
 are data points,  is the mean and n is the number of observations.
 is the mean and n is the number of observations.  


Sum of squares of differences = 642.1

We are given the following in the question:  
Population mean, μ = 106
Sample mean,  = 111.7
 = 111.7
Sample size, n = 10
Alpha, α = 0.05 
Sample standard deviation, s = 8.44
First, we design the null and the alternate hypothesis
 
 
We use one-tailed(right) t test to perform this hypothesis.
Formula:
 
 
Putting all the values, we have 
 
 
Now, 
 
 
Since,                  

We fail to accept the null hypothesis and reject it. We accept the alternate hypothesis.
We conclude that children in district are brighter, on average, than the general population.