It is reported that 10% of people are left-handed. A random sample of 15 people was drawn across the country to investigate this. a) Identify the "trial" here. Are trials independent? Explain your answer in the context of the question. b) Assume this is a proper binomial experiment. Define the binomial random variable in this question. How many possible values does it have? c) Find the mean of the binomial random variable and interpret this value in the context of the question. d) What is the probability that at least 4 but less than 8 are left-handed in this sample?