Text: Round to the nearest 4 digits
3. Taking the family to an amusement park has become increasingly costly according to the industry publication
Amusement Business, which provides figures on the cost for a family of four to spend the day at one of America's amusement parks. A random sample of 25 families of four that attended amusement parks yielded
the following costs, rounded to the nearest dollar. Obtain a 95% confidence interval for the mean cost of a family of four to spend the day at an American amusement park. x = $193.32; s = $26.73)
156 212 218 189 172 221 175 208 152 184 209 195 207 179 181 202 166 213 221 237 130 217 161 208 220
4. Phyllodes tumors of the breast are rare tumors that represent less than one percent of growths in the breast. Researchers presented characteristics of phyllodes tumors in the article. The following table provides summary statistics for the sizes, in millimeters, of independent samples of benign and malignant phyllodes tumors. At the
1% significance level, do the data provide sufficient evidence to conclude that, on average, malignant phyllodes tumors are larger than benign phyllodes tumors? Assume that the population standard deviations are not equal.
Malignant: n = 52, x = 48.5, s = 38.5
Benign: n = 116, x = 33.7, s = 26.6
a) State the null and alternative hypotheses
b) State the significance level
c) State the value of the test statistic (p)
d) Give the P-value
e) State your conclusion
5. Consumer reports publishes reviews and comparisons of products based on results from its laboratory. Data
from their website gave the following table for the battery lives, in hours, for samples of laptops made by four
different computer companies. The four brands are Apple, Dell, Samsung, and Toshiba, but we have not used the names and have permuted the order. At the 5% significance level, do the data provide sufficient evidence to conclude that a difference exists in mean battery life among the four brands? (This data can be found on Canvas
under file titled "Laptop Battery Life")
Brand A:
7.25 9.50 6.25 8.00 8.25 10.25 6.25 5.75
12.00 7.25 11.75 15.00 8.50 8.75 10.00 10.25
11.50 9.50 10.00 5.00 9.50 2 5.25 11.50
a) State the null and alternative hypotheses
b) State the significance level
c) State the value of the test statistic (p)
d) Give the P-value
e) State your conclusion
