The standard deviation of the lengths of hospital stay on the intervention ward is 7.4 days. Complete parts (a) through (c) below. *** a. For the variable "length of hospital stay," determine the sampling distribution of the sample mean for samples of 91 patients. The sampling distribution will be approximately normal with mean and standard deviation o- = (Round to four decimal places as needed.) b. The distribution of the length of hospital stay is right skewed. Does this invalidate your result in part (a)? Explain your answer. A. No, because the sample size is sufficiently large so that x will be approximately normally distributed, regardless of the distribution of x. O B. Yes, because the sample sizes are not sufficiently large that x will be approximately normally distributed, regardless of the distribution of x. OC. No, because if x is normally distributed, then x must be normally distributed. D. Yes, because x is only normally distributed if x is normally distributed. The probability is approximately