please do both questions and show all work

Question "11: Consider a normal population distribution whth the value of s known. a) What is the confidence level for the interval x22.81 ? b) What is the confidence level for the interval x1.44 ? c) What value of z/2 in the Cl formula (7.5) of the book results in a confidence level of 997% ? d) Answer the question posed in part (c) for a confidence level of 75%. Question \#2: Determine the confidence level for each of the following large-sample one-sided confidence bounds: a) Upper bound: x+0.84s b) Lower bound: x2.05s c) Upper bound: x+0.67s Question \#3: A study of the ability of individuals to walk in a straight line ("Can We Really Walk Straight?" Amer. J. of Physical Anthro., 1992: 19-27) reported the accompanying data on cadence (strides per second) for a sample of n=20 randomly selected healthy men. A normal probability plot gives substantial support to the assumption that the population distribution of cadence is approximately normal. A descriptive summary of the data from Minitab follows: a) Calculate and interpret a 95% confidence interval for population mean cadence b) Calculate and interpret a 95% prediction interval for the cadence of a single individual randomly selected from this population c) Calculate an interval that includes at least 99% of the cadences in the population distribution using a confidence level of 95%