1. You want to obtain a sample toestimate how much parents spend on their kids birthday parties.Based on previous study, you believe the population standarddeviation is approximately ?=26.2?=26.2 dollars. You would like tobe 99% confident that your estimate is within 2 dollar(s) ofaverage spending on the birthday parties. How many parents do youhave to sample?
2. You measure 27 watermelons' weights, andfind they have a mean weight of 30 ounces. Assume the populationstandard deviation is 7.4 ounces. Based on this, what is themaximal margin of error associated with a 90% confidence intervalfor the true population mean watermelon weight.
Give your answer as a decimal, to two places
3.
Statistics students in Oxnard College sampled 11 textbooks inthe Condor bookstore and recorded the number of pages in eachtextbook and its cost. The bivariate data are shownbelow:
| Number of Pages (xx) | Cost(yy) |
|---|
| 439 | 76.46 |
| 739 | 121.46 |
| 459 | 73.26 |
| 514 | 78.96 |
| 676 | 104.64 |
| 386 | 76.04 |
| 452 | 80.28 |
| 203 | 50.42 |
| 505 | 78.7 |
| 726 | 117.64 |
| 995 | 157.3 |
A student calculates a linear model
yy = xx + . (Please show your answers to two decimalplaces)
Use the model to estimate the cost when number of pages is949.
Cost = $ (Please show your answer to 2 decimal places.)
4.
Statistics students in Oxnard College sampled 11 textbooks inthe Condor bookstore and recorded the number of pages in eachtextbook and its cost. The data are shown below:
| Number of Pages (xx) | Cost(yy) |
|---|
| 288 | 47.56 |
| 978 | 134.36 |
| 716 | 95.92 |
| 672 | 89.64 |
| 759 | 105.08 |
| 571 | 80.52 |
| 515 | 78.8 |
| 239 | 34.68 |
| 584 | 94.08 |
| 586 | 90.32 |
| 503 | 73.36 |
A student calculates a linear model using technology (TIcalculator)
ˆyy^ = xx + . (Please show your answers to two decimalplaces)
Use the model to estimate the cost when number of pages is574.
Cost = $ (Please show your answer to 2 decimal places.)
