Problem 3. A researcher is interested in determining the mean age (in weeks) at which babiesfirst crawled. Based on a survey of mothers conducted by Essential Baby, the following datawas obtained.51, 31, 43, 36, 40, 25, 47, 37, 55, 27 , 39, 28. Treat the sample as a simple random sample of all the ages (in weeks) at which babies first crawl from a population that is approximately normally distributed. PART 1(a) Find the sample mean and the sample standard deviation and the number of subjects in the studies.This can be done by using the statistical software R or algebra.The c()command is used to enter your data by hand in R. An example using c() is on p.6 of the lecture notes. (c) Find the standard error of this estimate. Explain what this number means.
(d) What is the value of t-multiplier tα/2,n−1 for a 96% confidence interval? Round your
answer to 3 decimal places. Use four different ways to get this value
(e) Find the margin of error for a 96% confidence interval.
PART 2
(a) Find the 96 % confidence interval of the mean age at which babies first crawl. Interpret
the interval in context.
