It is known that the income in country A and income in country B both follow the normal distribution with the same variance.
A random sample of 10 people from country A gives a sample average of 50 and a sample variance of 16.
A random sample of 9 people from country B gives a sample average of 70 and a sample variance of 16 .
Run a test of whether the population mean income in country B is 10 units higher than that of country A. Choose significance level 5 per cent.
What should you conclude?
O The absolute value of the test statistic is approx. 10.88. The critical values are plus/minus 2.11 . Thus, we cannot reject the null hypothesis that country B's population mean is 10 units higher than that of country A at significance level 5 per cent.
O The absolute value of the test statistic is approx. 5.44. The critical values are plus/minus 2.11. Thus, we cannot reject the null hypothesis that country B's population mean is 10 units higher than that of country A at significance level 5 per cent.
O The absolute value of the test statistic is approx. 10.88. The critical values are plus/minus 2.11 . Thus, you should reject the null hypothesis that country B's population mean is 10 units higher than that of country A at significance level 5 per cent.
The absolute value of the test statistic is approx. 5.44. The critical values are plus/minus 2.11 . Thus, you should reject the null hypothesis that country B's population mean is 10 units higher than that of country A at significance level 5 per cent.