Question: You may recall that on January 28, 1986, the space shuttle Challenger exploded moments after takeoff, killing all on board, due to an O-ring failure that caused fuel to leak and ignite. The temperature at the Kennedy Space Center that morning was 31º F (-0.5º C). Before the launch, some scientists expressed concern that the low temperature might cause hardening and failure of the O-rings. Other scientists refuted this, based on the data in the file Challenger1.xlsx, which records the temperature at the launch site and the number of failures for flights that had an O-ring failure.

a) On the basis of the data in the file Challenger1.xlsx, which group of scientists was right? Is there a relationship between number of O-ring failures and temperature?

b) A post-crash follow-up commission collected data for temperature and number of O-ring failures on all 24 of the successful pre-Challenger flights, contained in the file Challenger2.xlsx. Use this data to establish whether there is a relationship between O-ring failure and temperature.