The Australian dragonfly, the world's fastest insect, has been clocked at 36 miles per hour over short distances. A biologist captured 25 Australian dragonflies and she recorded the average wingspan of these captured dragonflies of 6.6cm. The biologist assumed that the wingspan is normally distributed with a standard deviation of 0.5cm.
a. Find a 98.3% confidence interval for the true mean wingspan for all dragonflies.
b. Interpret the interval obtained in part (a) in the context of this question.
c. If a 90% confidence interval for the true mean wingspan for all dragonflies is calculated, do you expect this interval be wider or narrower than the interval obtained in part (a)? Why?
d. If the biologist assumed that the standard deviation of the wingspan of Australia dragonfly is 0.25cm and a 98.3% confidence interval for the true mean wingspan for all dragonflies is calculated, do you expect this interval be wider or narrower than the interval obtained in part (a)? Why?