Among various ethnic groups, the standard deviation of heights is known to be approximately three inches. We wish to construct a 95% confidence interval for the mean height of males from a certain country. Forty-five males are surveyed from a particular country. The sample mean is70inches.The sample standard deviation is2.9inches.

• Part (a)
• Find the following. (Enter exact numbers as integers, fractions, or decimals.)
• (i)x=70
• (ii)= (is not 2.9)
• (iii)n=45
• Part (b)
• Construct a 95% confidence interval for the population mean height of males of this country.
• (i) State the confidence interval. (Round your answers to two decimal places.)
• (__________,__________)
• (ii) Sketch the graph.
• (iii) Calculate the error bound. (Round your answer to two decimal places.)