Expands (sd_mult > 1) or reduces (sd_mult < 1) the standard deviation
of the Log-Normal distribution. With high values of sdlog (i.e., > 9),
and sd_mult > 1, the mean of the adjusted distribution can be expected to
have a mean value that is very different from the original mean, however,
the proportional difference in these values should not be very different.
See also
Other sens_dist:
sens_beta(),
sens_exp(),
sens_gamma(),
sens_gamma_pois(),
sens_gamma_pois_zi(),
sens_neg_binom(),
sens_norm(),
sens_pois(),
sens_skewnorm(),
sens_student()
