1. Use of bed nets. A study found that the use of bed nets was associated with a lower prevalence of malarial infections in the Gambia.13 A report of the study states that the signi?cance is P 0.001.
Explain what this means in a way that could be understood by someone who has not studied statistics.
2. Purity of a catalyst. A new supplier offers a good price on a catalyst used in your production process. You compare the purity of this catalyst with that of the catalyst offered by your current supplier. The P-value for a test of "no difference" is 0.27. Can you be con?dent that the purity of the new product is as being statistically signi?cant. Explain what this means in simple terms and offer an explanation for why the health and safety students had a higher mean score.