PART 3 A car mat manufacture been having quality issues with its production. A series of tests were carried out to measure the resulting pH of the most common carpet produced, Type 1, as a good...

PART 3

A car mat manufacture been having quality issues with its production.  A series of tests were carried out to measure the resulting pH of the most common carpet produced, Type 1, as a good indicator of quality.

For the following questions show all calculations and formula used

.

• What is the mean, mode and range of the pH after dyeing?

Table – Type 1

• For pH after addition of dye calculate the standard deviation, showing your calculations in full.

• Plot the standard deviation graph in Excel showing the distribution.

• From your calculations and the data

1. Give the minimum and maximum limits the pH may be, given that the distribution is normal.


2. Calculate the probability that a randomly selected carpet sample will have a PH of (i) 6.1 and (ii) 5.4.

• Further tests were carried on a large sample of all carpet types and the following distribution was obtained. It is believed that the carpet type does not affect the pH.  Test this hypothesis and whether there is a correlation or not. ( Data for 1 type of carpet)

• Finally present the statistical data you have been investigating a manner that can be understood by non-technical management at the carpet factory.