Question

4. An engineer wants to find an estimate of a specific concrete tension strength and takes 5 repeated measurements using a UTM machine obtaining 52, 47, 51, 53, and 49 MPa. a) (5 pts) What is the tension strength of the concrete? b) (5 pts) Estimate the uncertainty in the measurement c) (5 pts) The UTM is recalibrated so the bias is negligible, a new sample is measured to be 55.1 MPa. How does this last measurement should be expressed?

Answer 1

Solution - miven that S tarted given are the sample obscorvations: 52, 49, 51, 53,49 car. The tensile strength of the concorete = Exi - 52+ 47+51 +53+49 = 50.4 MPa (b). The uncertainity in the measuremont - Tecxi x2 = (52-50-43+ --.-7649-50144)2 5-1 2-4083mpa

(C7 now, that the blas is removed, a new sample is measured to be 551. mpa can be exporessed in the This 5501 mpa form of old mean 1.e. 5511= 50'4+30 x inceontainity C = 5501 - 5014 2-4083 1911.9 -. x = L-9121.9 Therefore, this new sample can be expressed as 50.4+119(2:4) Thank you