Crickets make their chirping sounds by rapidly sliding one wing over the other. The faster they move their wings, the higher the number of chirping sounds that are produced. Scientists have noticed that crickets move their wings faster in warm temperatures than in cold temperatures (they also do this when they are threatened). Therefore, by listening to the pitch of the chirp of crickets, it is possible to tell the temperature of the air. The following table gives the number of cricket chirps per 13 s recorded at 10 different temperatures. Assume that the crickets are not threatened.

Calculate the least-squares regression line for these data and discuss its usefulness.

Temperature Number of chirps 20 25 31 33 36 39 42 48 49 52 60 66 70 73 78 80 82 87 90 92