A British statistician and biologist introduced a data set which consists of 50 samples from Iris setosa. The length of sepals was measured from each sample in centimetres. A long-term study says that the average length of sepals of Iris setosa is 5.5 centimetres. The data set is available as Excel file "iris setosa sepal length.xlsx" on Moodle in the "Assessment" block.

1. What conditions are needed to proceed with inference using this data? Perform a check to show that the conditions are valid.

1. Determine if the data provides evidence that the mean sepal length of Iris setosa is different to the traditional 5.5 cm, by
   1. constructing a 95% confidence interval, and

1. conducting a suitable test at the 5% significance level.

1. Is the conclusion from the confidence interval calculation above the same as the conclusion of the test above? Explain why or why not.

Below is the data set