A US congressman published a narrative. In an article, researchers determined that x, the number of times (per 1 comma 000 words) that the word "though" appears in the narrative, has a mean of 0.27. Assume that x has an approximate Poisson distribution. Complete parts a through c. Question content area bottom Part 1 a. Find the variance of x. sigma squaredequals 0.27 (Type an integer or a decimal. Do not round.) Part 2 b. Calculate the interval mu plus or minus 2 sigma. What proportion of the time will x fall into this interval? Calculate the interval mu plus or minus 2 sigma. left parenthesis nothing comma nothing right parenthesis (Type integers or decimals rounded to two decimal places as needed.) Part 3 What proportion of the time will x fall into this interval? pequals enter your response here (Type an integer or decimal rounded to four decimal places as needed.)