Excel was asked to generate 50 poisson random numbers with mean λ = 5. x frequency 0 1 1 1 2 4 3 7 4 7 5 8 6 10 7 3 8 3 9 4 10 1 11 1 click here for the excel data file (a) calculate the sample mean. (round your sample mean value to 2 decimal places.) sample mean (b) carry out the chi-square test at α = .05, combining end categories as needed to ensure that all expected frequencies are at least five. (round your test statistic value to 3 decimal places and the p-value to 4 decimal places.) test statistic d. f. p-value (c) the observations were coming from a poisson distribution. true false