BBM203: Business Statistics Assignment, WOU, Malaysia Explain the difference between paired and unpaired samples in a hypothesis testing procedure involving two sample means

Question 1

Explain the difference between paired and unpaired samples in a hypothesis testing procedure involving two sample means. Give one (1) suitable example for each type of sample selection.

Question 2

List two (2) applications of standardized normal distribution.

Question 3

When a certain production machine is in perfect adjustment it produces bolts with a mean diameter of 0.6 cm and a standard deviation of 0.15cm. In order to ascertain whether or not the machine is still in adjustment, a sample of 49 bolts is selected. The sample means the diameter is found to be 0.57cm. Is the machine still in adjustment?

Question 4

A company is interested in knowing if there is a difference in the average salary received by the machine operator for two departments. According to the samples, 18 machine operators from Department A and 13 machine operators from Department B are selected randomly and the following information is obtained:

Question 5

A quality control inspector keeps a tally sheet of the number of acceptable and
unacceptable products that come off two different production lines. The completed sheet is shown below.

• Can the inspector infer at the 5% significance level that production line A is
  doing a better job than production line B?
• What is the p-value of the test?
• Estimate with 95% confidence the difference in population proportions.