The time it takes a pizza delivery driver to reach his destination for a sample of 28 deliveries has a mean of 36 minutes. The standard deviation of those 28 deliveries is s = 2 minutes. Construct an 85% confidence interval to estimate the true mean of all his pizza deliveries. (35.440,36.560) (27.520,28.480) (35.259,36.741) (27.347,28.653)

The length of human pregnancies from conception to birth is known to be normally distributed with a mean of 266 days and standard deviation of 16 days. A pregnancy longer than "nine months" might be considered as 274 days or longer (four months have 30 days, and February has 28 in most years). What proportion of pregnancies last more than "9 months?" First, find the z-score for 274: (274 -266)/16 0.5. Then, find the area to the of 0.5, using the table. Your answer Need help on this question? Read the ebook page on this topic (1no penaltyi Geta hint (fewer pelnte Show answer (nopoint

A sample is selected from a population with = 150. After a treatment is administered to the individuals, the sample mean is found to be = 140 and the standard deviation is S= 9. If the sample has n = 18 scores, determine whether the sample is sufficient to conclude that the treatment has significant effect. Use a two tail test with = 0.02.

A random sample of 51 adult coyotes in a region of northern Minnesota showed the average age to be x = 1.99 years, with sample standard deviation s = 0.70 years. However, it is thought that the overall population mean age of coyotes is ? = 1.75. Do the sample data indicate that coyotes in this region of northern Minnesota tend to live longer than the average of 1.75 years? Use ? = 0.01.   (a) State the null hypotheses  H0  and the alternate hypothesis  H1 . H0 : ?          H1 : ?         (b) What is the value of the sample test statistic? (Round your answer to three decimal places.)(c) Calculate the P-value. (Round your answer to four decimal places.)Sketch the sampling distribution and show the area corresponding to the P-value.Graph!         will you reject or fail to reject the null hypothesis? Are the data statistically significant at level ?? At the ? = 0.01 level, we reject the null hypothesis and conclude the data are statistically significant.At the ? = 0.01 level, we…

A random sample of 78 eighth grade students scores on a national mathematics assessment test has a mean score of 289. This test result promos a state school administrator to declare that the mean score for the states eight graders on this exam is more than 285. Assume that the population standard deviation is 36. At x=0.03, is there enough evidence to support the administrators claim?