Reference no: EM132391348
BUGEN1502 Business Statistics
Assignment : Confidence Interval and Hypothesis testing
Background
A researcher is interested in the average time for a package to arrive in Australia from a seller based in Hong Kong. The time is the days from the time of ordering to the time of arrival in Australia (in days). A random sample of the packages is selected.
Questions
Question 1
1) Use Excel to obtain an appropriate histogram for the values for the arrival time. The interval in the table is to be used for creating the histogram.
2) Briefly state what the histogram is telling us about the distribution of the data.
3) Calculate the descriptive statistics.
4) Explain the distribution, central tendency and variation.
Question 2
1) Calculate the 95% confidence interval of the population mean, assume that the population standard deviation is known (σ = 5.80).
2) Calculate the 95% confidence interval of the population mean, assuming that the population standard deviation is unknown.
Question 3
In the past it has been found that the arrival time have a population mean value of μ = 13 days.
Assume that the population standard deviation is unknown. The significance level alpha is set at 5%.
1) The research wants to know whether this mean has changed. Test the hypothesis with the critical value approach.
2) The research wants to know whether the mean is more than 13 days. Test the hypothesis with p value approach.
Question 4
1) Explain the meaning of p value.
2) What is the advantage of p value approach over critical value approach?
3) Does a small p value indicate a strong relationship between the studied variables? Give your reason.
4) If a p value of a one tailed test is 0.04, what is the p value for a two tailed test?
Attachment:- Assignment Data.rar