Question

16.) Snails are a great known biological indicator of radiation levels in an environment due to their ability to retain radiation levels for 2 months after exposure. A snail species by Chernobyl is known to have a mean width of 4.75 cm. Following the Chernobyl reactor meltdown of 1986 scientists have been concerned about how the growth of different animals may be affected. One scientist was worried about the snails and how their width might be affected by the radiation.

a.) Formulate the null and the alternative hypotheses to test the scientist's concern for snails.  

b.) A random sample of 26 snails was taken and their width was recorded for each snail. The summary statistics were: x̄=4.66 cm and s=0.25 cm. Assume that the width of the snails is normally distributed. Calculate the value of the test statistic for the hypotheses from part a, state the degrees of freedom, and find the approximate p-value.

c.) Would you reject H₀ or fail to reject H₀ at a 5% level of significance?

d.) What would you conclude about the mean width of the snails after the reactor meltdown?  

Answer 1