An operator wants to determine the standard deviation for a machine relative to its ability to produce windshield wipers conforming within their specifications. To do this, she wants to create a p-chart. Over a month's time, she tests 100 units every day and records the number of manufacturing defects. The average proportion of non-conforming windshield wipers is found to be 0.042. What is the standard deviation of this sample

Respuesta :

Answer:

the standard deviation of the sample is less than  0.1

Step-by-step explanation:

Given that :

The sample size n = 100 units

The average proportion of non-conforming windshield wipers is found to be 0.042 which is the defective rate P-bar

The standard deviation of the machine([tex]S_p[/tex]) can be calculated  by using the formula:

[tex]S_p =\dfrac{ \sqrt{ \overline P \times (1 - \overline P)} }{n}[/tex]

[tex]S_p =\dfrac{ \sqrt{0.042 \times (1 -0.042)} }{100}[/tex]

[tex]S_p =\dfrac{ \sqrt{0.042 \times (0.958)} }{100}[/tex]

[tex]S_p =\dfrac{ \sqrt{0.040236} }{100}[/tex]

[tex]S_p =\dfrac{ 0.2005891323 }{100}[/tex]

[tex]S_p =0.002[/tex]

Thus , the standard deviation of the sample is less than  0.1