6. The percent of contents of ashes in coal is a normally distributed random variable with mathematical expectation 20% and dispersion 9%. Find: a) the differential and
integral functions of distribution; b) the probability that a randomly taken test of coal
will contain from 18 up to 28% of ashes (ashes - 303a; coal -yrob).​

nataliamoroz830    1   20.10.2020 09:09    4