Final answer:
The sampling error is 1.44. The critical values χ2R and χ2L for c=0.95 and n=18 are 30.191 and 7.564 respectively.
Step-by-step explanation:
To find the sampling error, subtract the true value from the observed value. In this case, u=24.41 and x=25.85. So, the sampling error is 25.85 - 24.41 = 1.44.
To find the critical values χ2R and χ2L for the given confidence level c=0.95 and sample size n=18, first find the degrees of freedom df = n - 1 = 18 - 1 = 17. Then, use a chi-square distribution table or a calculator to find the critical values. For a confidence level of 0.95 and 17 degrees of freedom, the critical values are χ2R = 30.191 and χ2L = 7.564.