A random sample of 29 glass sheets is obtained and their thicknesses are measured. The sample mean is x= 3.12 mm and sample standard deviation is S = 0.14 mm. Construct a 95% two-sided confidence interval for the mean glass
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A random sample of 29 glass sheets is obtained and their thicknesses are measured. The sample mean is x= 3.12 mm and sample standard deviation is S = 0.14 mm. Construct a 95% two-sided confidence interval for the mean glass thickness
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- The mean number of the sample of 16 bolts produced on a specific machine per day was found to be 42 with a standard deviation of 2. Assume that the number of bolts produced per day on this machine has a normal distribution. Construct a 95% confidence interval for the population mean A tyre manufacturer claims that its tyres have a mean life of 50000 kms. A random sample of 16 of these tyres is tested and the sample mean is 33 000 kms. Assume the populations standard deviation is 3000kms and the lives of tyres are approximately normally distributed. To test the manufacturer’s claim using the 5% level of significance the analyst shouldIn a random sample of twelvetwelve people, the mean driving distance to work was 24.624.6 miles and the standard deviation was 4.54.5 miles. Assume the population is normally distributed and use the t-distribution to find the margin of error and construct a 9999% confidence interval for the population mean muμ. Interpret the results.
