Question

Consider the accompanying data on flexural strength (MPa) for concrete beams of a certain type

 5.8 9.7 7.0 7.0 7.0 7.8 10.7 

 7.4 6.5 7.8 6.3 7.2 6.3 8.1 

 11.6 9.7 7.7 11.3 9.0 7.7 6.8 

 8.9 7.4 8.7 7.3 6.8 11.8 

 (a) Calculate a point estimate of the mean value of strength for the conceptual population of all beams manufactured in this fashion. 

 (b) Calculate a point estimate of the strength value that separates beams from the strongest 50% State which estimator you used. 

 (c) Calculate a point estimate of the population standard deviation σ.  

 Interpret this point estimate.

•  This estimate describes the center of the data.

•  This estimate describes the bias of the data.

•  This estimate describes the linearity of the data.

•   This estimate describes the spread of the data.

 which estimator did you use?

 (d) Calculate a point estimate of the proportion of all such beams whose hexural strength exceeds 10 HPa. 

 (e) Calculate a point estimate of the population coefficient of variation σ/μ.  

Answer 1