Correlation regression
http://www.mathsisfun.com/data/standard-normal-distribution-table.html (Z table)
http://www.sjsu.edu/faculty/gerstman/StatPrimer/t-table.pdf (t table)
Critical Values (Z) Level of Significance 1% 2% 4% 5% 10%
Two Tailed ±2.56 ±2.32 ±2.05 ±1.96 ±1.64
Right tailed +2.32 +2.05 +1.75 +1.64 +1.28
Left tailed -2.32 -2.05 -1.75 -1.64 -1.28
Q1) A cinema hall has cold drinks fountain supplying Orange and Ditzy Colas. When the machine is turned on, it fills a 550ml cup with 500ml of the required drink. The manager has three problems.
I) The clients have been complaining that the machine supplies less than 500ml
II) The manager wants to make sure that the amount of cola does not exceed 500ml
III) The manager wants to minimize customer complaint and at the same time does not want any overflow.
He takes up 36 cups of sample and finds the sample mean to be 499 ml. The specification of the machine says that generally the standard deviation is 1 ml. He does a hypothesis testing at 10% level of significance.
Q2) A tyre company wants to test the stress of tyres. The tyres should withstand a minimum load of 80,000kgs but excess load would burst the tyres. From the past experience, it is known that the standard deviation of the load is 4000kgs. A sample of 100 tyres was selected and tests were carried out. The result showed that mean stress capacity of the sample is 79,600 kgs. If the supplier uses a significance level of 5% in testing, do the tyres meet stress requirements? Also, find the limits of the acceptance region (or confidence limits).
Q3) A random sample of 400 flower stems has indicated that the average length of a stem is 10cm. Can this be regarded as a sample from a large population with a mean of 10.2cm and a standard deviation of 2.25cm at a significance level of 5%?
Q4) The height of 10 soldiers selected at random had a mean height of 158cm and variance of 39.06 cms. Assuming a significance level of 5%, test the hypothesis that the
http://www.sjsu.edu/faculty/gerstman/StatPrimer/t-table.pdf (t table)
Critical Values (Z) Level of Significance 1% 2% 4% 5% 10%
Two Tailed ±2.56 ±2.32 ±2.05 ±1.96 ±1.64
Right tailed +2.32 +2.05 +1.75 +1.64 +1.28
Left tailed -2.32 -2.05 -1.75 -1.64 -1.28
Q1) A cinema hall has cold drinks fountain supplying Orange and Ditzy Colas. When the machine is turned on, it fills a 550ml cup with 500ml of the required drink. The manager has three problems.
I) The clients have been complaining that the machine supplies less than 500ml
II) The manager wants to make sure that the amount of cola does not exceed 500ml
III) The manager wants to minimize customer complaint and at the same time does not want any overflow.
He takes up 36 cups of sample and finds the sample mean to be 499 ml. The specification of the machine says that generally the standard deviation is 1 ml. He does a hypothesis testing at 10% level of significance.
Q2) A tyre company wants to test the stress of tyres. The tyres should withstand a minimum load of 80,000kgs but excess load would burst the tyres. From the past experience, it is known that the standard deviation of the load is 4000kgs. A sample of 100 tyres was selected and tests were carried out. The result showed that mean stress capacity of the sample is 79,600 kgs. If the supplier uses a significance level of 5% in testing, do the tyres meet stress requirements? Also, find the limits of the acceptance region (or confidence limits).
Q3) A random sample of 400 flower stems has indicated that the average length of a stem is 10cm. Can this be regarded as a sample from a large population with a mean of 10.2cm and a standard deviation of 2.25cm at a significance level of 5%?
Q4) The height of 10 soldiers selected at random had a mean height of 158cm and variance of 39.06 cms. Assuming a significance level of 5%, test the hypothesis that the