The economic dynamism, which is the index of productive growth in dollars for countries that are designated by the World Bank as middle-income are in the table below. Countries that are considered high-income have a mean economic dynamism of 60.29.
Table: Economic Dynamism ($) of Middle Income Countries
| 25.8057 | 37.4511 | 51.915 | 43.6952 | 47.8506 | 43.7178 | 58.0767 |
| 41.1648 | 38.0793 | 37.7251 | 39.6553 | 42.0265 | 48.6159 | 43.8555 |
| 49.1361 | 61.9281 | 41.9543 | 44.9346 | 46.0521 | 48.3652 | 43.6252 |
| 50.9866 | 59.1724 | 39.6282 | 33.6074 | 21.6643 |
(a) Set up and run a test of hypotheses to determine if the data show that the mean economic dynamism of middle-income countries is less than the mean for high-income countries? Use a level of significance of 5%. Specifically, do the following:
(i) Write down the null and alternative hypotheses.
(ii) Verify that the assumptions necessary to apply the test are satisfied.
(iii) What is the test statistic and what is the p-value?
(iv) State your conclusion.
(b) Using the data in the table which represents the index of productive growth in dollars for countries that are designated by the World Bank as middle-income, construct a 95% confidence interval for the true mean economic dynamism of middle-income countries. Make sure to check the assumptions necessary to construct the interval. Interpret the interval.
