Question

Pheromones in Female Tears? Studies were conducted to investigate whether there is evidence of pheromones (subconscious chemical signals) in female tears that affect sexual arousal in men. In one of the studies,150 men had a pad attached to the upper lip that contained either female tears or a salt solution dripped down the same female's face. Each subject participated twice, on consecutive days, once with tears and once with saline, randomized for order, and double-blind. Testosterone levels were measured before sniffing and after sniffing on both days. While normal testosterone levels vary significantly between different men, average levels for the group were the same before sniffing on both days and after sniffing the salt solution (about 155 pg/mL) but were reduced after sniffing the tears (about 133 pg/mL). The mean difference in testosterone levels after sniffing the tears was 21.7 with standard deviation 46.5 2011,331(6014) 226-230 1 Data approximated from Gel stein, S., et. al., "Human Tears Contain a Chemosignal," Science, 14 January 2011: 331 (6014): 226-23o. (a) Test to see if testosterone levels are significantly reduced after sniffing tears. Give the test statistic and the p-value. Round your answer for the test statistic to two decimal places and your answer for the p-value to three decimal places. test statistic p-value

Answer 1

H0: mu(d) = 0
Ha: mu(d) not equals 0

xbar = 21.7 and s = 46.5
n = 50

Test statistic,
t = (xbar - 0)/(s/(sqrt(n))
t = (21.7 - 0)/(46.5/sqrt(50))
t = 3.30

This is two tailed test,
p-value = 0.002