You measure 20 dogs' weights, and find they have a mean weight of 40 ounces. Assume the population standard deviation is 9.5 ounces. Based on this, construct a 95% confidence interval for the true population
a) 36.701 to 43.299 ounces
b) 37.985 to 42.015 ounces
c) 38.207 to 41.793 ounces
d) 39.041 to 40.959 ounces