Reference no: EM133265335
An investigator believes that families in Virginia have more children on average than the average number of children in the population of the United States. From census data the investigator knows that the mean number of children in the U.S. is 2.1 children. She draws a sample of seven families from the state of Virginia and obtains the following numbers of children for the seven families: 3, 6, 2, 1, 4, 6, 7.
A) Suppose the true mean number of children in Virginian families is 2.1, so the null hypothesis is correct and should not be rejected. Based upon this information, is your conclusion in part (c) the right decision? If not, what kind of error (Type I or II) did you make?
B) Suppose your sample did not include the family with 7 children. Without using any computations from your spreadsheet, would your new 95% confidence interval shift to the left (closer to zero) or the right (further from zero)? Explain your answer.
C) Suppose your sample did not include the family with 7 children. Without using any computations from your spreadsheet, would your new 95% confidence interval be narrower or wider? Explain your answer.