Hi tutor,

Please find the attached Statkey to answer all questions.

Question 2 (Confidence Interval)

The Smiles dataset contains results from an experiment that studied the effects of smiling and leniency in judging students accused of cheating. The population parameter of interest is a difference in meanss-n, wheresandnare the average leniency scores for smiling students and students with neutral expression, respectively.

In answering the questions below make sure you use appropriate notation where necessary.

(i)By using the generated Statkey, describe the shape and centre of your bootstrap distribution in one or two sentences.?

(ii)Using percentiles from your bootstrap distribution, find and interpret in context a 90% confidence interval for the difference in means in one or two sentences.?

(iii)At 90% confidence, is it plausible that smiling has no effect on leniency? Justify your answer in one or two sentences.?

(iv)Repeat parts (ii) and (iii) replacing 90% confidence with 99% confidence.?

Confidence Interval for a Difference in Means ' Smilesxsv: Leniency (by Group) v Show Data Table Edit Data Upload File Change Column(s) l ' Generate 1 Sample Generate 10 Samples Generate 100 Samples Generate 1000 Samples Reset Plot ' Bootstrap Dotplot of f1 :72 Original Sample f1 -f2 = 0,79, 7:, = 34, n2 =34 C] Left Tail D TwoTail Right Tail samples = 10000 300 mean = 0.790 ml. error = 0.383 neutral 250 smile 200 2 3 4 15 6 7 s 9 4.912 150 Bootstrap Sample Show Data Table 1 2122:\