The u. s. public health service’s advisory committee on immunization practices recommends a tetanus booster every 10 years. suppose the lifetime (in years) of a tetanus booster shot has an exponential distribution with an average of 17 years. a) find the value of λ. include at least four decimal places. b) what is the standard deviation of the length of time that a tetanus booster will last? c) find the probability that a randomly selected tetanus booster shot is still protecting against tetanus after more than 10 years. d) find the probability a randomly selected tetanus booster shot is still protecting against tetanus between 10 and 15 years.