RELIABILITY

MEM 361: ENGINEERING RELIABILITY

Winter 2017_2018

Home work #5

Due: 02/22/2018

Performance indicators: 1,2,4,5

marks: 100

Use the data provided in the attached document ‘Marks’.

The data given are the marks m obtained by students in a class.

Fit the data to a normal distribution: estimate mean m, standard deviation m and plot the pdf(m).

Except for the scatter plot and linear curve-fit, you SHOULD NOT use any built in

function. Show these steps and calculations: ordering the data, usage of mean ranking,

determining the ‘zi’ points (you may use built in command instead of Appendix of the

Text), scatter plot, the linear fit, calculation of mean and std, and the pdf-plot.

Set up the grade distribution as given below and determine the percentages of the grades

{A,B,C,D,F} obtained.

Grade Distribution:

{ 𝑚 ≥ 𝜇𝑚 + 3

2 𝜎𝑚 } ⇒ 𝐴

{ 𝜇𝑚 + 1

2 𝜎𝑚 ≤ 𝑚 < 𝜇𝑚 +

3

2 𝜎𝑚 } ⇒ 𝐵

{ 𝜇𝑚 − 1

2 𝜎𝑚 ≤ 𝑚 < 𝜇𝑚 +

1

2 𝜎𝑚 } ⇒ 𝐶

{ 𝜇𝑚 − 3

2 𝜎𝑚 ≤ 𝑚 < 𝜇𝑚 −

1

2 𝜎𝑚 } ⇒ 𝐷

{ 𝑚 < 𝜇𝑚 − 3

2 𝜎𝑚 } ⇒ 𝐹