Suppose germination periods, in days, for grass seed are normally distributed and have a known population standard deviation of 2 days and an unknown population mean. a random sample of 22 types of grass seed is taken and gives a sample mean of 46 days. find the error bound (ebm) of the confidence interval with a 90% confidence level.

Let be the population mean .

Given : Sample size : n=22

Population standard deviation:

Sample mean :

z-value for 91% confidence level :

The formula to find the error bound (EBM) :

Then , the error bound (EBM) of the confidence interval with a 90% confidence level will be :-

Thus , the error bound (EBM) of the confidence interval with a 90% confidence level: E=0.7014

Furthermore , the 90% confidence interval will be :-

225x²+4=0

225x²=0-4

225x²=-4

x²=-4/225

x=±√-4/225