Gavin recently got a bad haircut and wants to know if eating lots of protein will help hair grow back faster. He asks 18 people to eat only meat for all of their meals every day for a month. Then, he measures how many centimeters their hair grew in that time. Gavin found that his sample's hair grew an average of 3cm, with a standard deviation of .5. He found that the general population (people who eat normally) has an average hair growth of 2.9 cm in one month. Unfortunately, Gavin could not find out what the general population's standard deviation for hair growth within one month was. a. Which analysis will you use for these data? (highlight one) single sample t I z test b. Null hypothesis: c. Alternative hypothesis: