In: Statistics and Probability
We are interested in estimating the mean systolic blood pressure for female diabetics between the ages of 30 and 34. For the purposes of this question you may assume that blood pressure in this population has a normal distribution with standard deviation of 11.8 mmHg.
a. A random sample of 10 women is selected from this population. The average systolic blood pressure in this sample is 130 mmHg. Calculate (by hand) a 95% confidence interval ,the mean systolic blood pressure in the population of female diabetics aged 30 to 34.
b. Interpret your confidence interval in a) in words. (What does “95% confidence” mean?)
c. Is your confidence interval in a) exact or approximate? Explain.
d. How large would the random sample of women need to be for a 99% confidence interval to have a total width of 10 mmHg?
b)We are 95% confident that mean systolic blood pressure for female diabeticsbetween ages of 30 and 34 will be between 121.5587885 and 138.4412115.
c) The confidence interval is not exact because we are approximating the sampling distribution of sample mean here.So our confidence interval of part a) is approximate