Hi I need help on what is the answer to this problems? Below is the question and other concerns will be in the comment section. I hope you can help me and surely I will give you full positive feedback.

1-2

2. Given a normal distribution where x = 72, # =65, and o = 3, find the value of z. 3. Given a normal distribution with a mean of 150, o = 10, and x = 2.5, what is the corresponding value of x?1. Let X be a random variable with values 4, 5, 7, 8, and 9. a. Find the mean and the variance of the samples without replacement if n = 2. b. Find the sampling distribution of the mean and construct its histogram. 2. Find the probability distribution of the mean of the possible outcomes from three balls numbered 4, 6, and 9, where n = 2 with replacement. Construct the histogram of the sampling distribution. (Hint: Use a tree diagram to get the total possible outcomes/samples.) 3. Let X be a random variable with values 2, 3, 5, and 6. Find the sampling distribution of the mean of the samples without replacement if n = 3. Compute the variance and the standard deviation. 4. An electrical firm manufactures light bulbs that have a mean life span of 750 hours with a standard deviation of 30 hours. Assume that the mean life span of the manufactured light bulbs is almost normally distributed. If a sample of 25 light bulbs are randomly selected, find the: a. probability that their mean life span is 770 hours b. probability that their mean life span is less than 740 hours c. probability that their mean life span is greater than 775 hours