Womens height is a suspected factor for difficult deliveries, that is, shorter women are more likely to have Caesarean sections. A medical researcher found in a sample of 45 women who had a normal delivery that their mean height was 61.4 inches. A second sample of 39 women who had a Caesarean section had a mean height of 60.6 inches. Assume that the population of heights of normal deliveries has a population standard deviation of 1.2 inches. Also assume that the heights of the population of women who had Caesarean section births has a standard deviation of 1.1 inches. Are those who had a Caesarean section shorter? Use the .05 significance level. Find the p-value and explain what it means.

1.1Statistics EX: (look at notebook) Noise (the spread of the dots): normal or expected variability Signal: fertilizer 1.2Types of Evidence I. Types of Evidence a. Anecdotal: something that sparks a study of investigation. A single instinct that can lead. i. EX: (A plane trip) A mom stops the babies from crying by giving it a juice box b. Observational: when researcher systematically collects data as an observer. NO manipulation. c. Experimental: researchers manipulate conditions – usually treatments, controls, randomness d. Placebo group: drug trials II. Concerns a. EX: flyin