Let æ be a random variable representing the percentage of protein content for early bloom alfalfa hay. The average percentage protein content of such early bloom alfalfa should be u = farmer's co-op is thinking of buying a large amount of baled hay but suspects that the hay is from a later summer cutting with lower protein content. A small amount of hay was removed from each bale of a random sample of 50 bales. The average protein content from the samples was determined by a local agricultural college to be -15.8% with a sample standard deviation of 17.2%. A s = 5.3%- At a = .05, does this hay have lower average protein content than the early bloom alfalfa?

A random selection of volunteers at a research institute has been exposed to a weak flu virus. After the volunteers began to have flu symptoms, 20 of them were given multivitamin tablets daily that contained 1 gram of vitamin C and 3 grams of various other vitamins and minerals. The remaining 20 volunteers were given tablets containing 4 grams of vitamin C only. For each individual, the length of time taken to recover from the flu was recorded. At the end of the experiment the following data were obtained. Treated with multivitamin Treated with vitamin C Days to recover from flu 3.2, 7.3, 8.4, 6.1, 2.5, 6.7, 6.3, 3.7, 7.0, 7.7, 9.1, 9.9, 9.0, 2.6, 2.0, 5.1, 5.7, 2.5, 2.9, 4.5 2.7, 5.3, 3.7, 5.5, 4.5, 3.8, 7.6, 5.3, 3.6, 5.2, 2.3, 4.7, 3.6, 5.2, 2.3, 7.1, 3.3, 6.1, 7.9, 4.2 Send data to calculator. Send data to Excel Suppose that it is known that the population standard deviation of recovery time from the flu is 1.8 days when treated with multivitamins and that the population standard…

Bighorn sheep are beautiful wild animals found throughout the western United States. Let x be the age of a bighorn sheep (in years), and let y be the mortality rate (percent that die) for this age group. For example, x = 1, y = 14 means that 14% of the bighorn sheep between 1 and 2 years old died. A random sample of Arizona bighorn sheep gave the following information: x 1 2 3 4 5 y 13.8 19.3 14.4 19.6 20.0 Σx = 15; Σy = 87.1; Σx2 = 55; Σy2 = 1554.45; Σxy = 274b) Find the equation of the least-squares line. (Round your answers to two decimal places.) ŷ =  +  x (c) Find r. Find the coefficient of determination r2. (Round your answers to three decimal places.) r =   r2 =     d) Test the claim that the population correlation coefficient is positive at the 1% level of significance. (Round your test statistic to three decimal places.) t =

Getting an adequate amount of sleep can improve a variety of physiological functions, and it is known that the average number of hours that people sleep each night is normally distributed. A psychiatrist or a major research center takes an SRS of 25 emotionally disturbed patients and records the average amount of sleep that each gets on a typical night. He summarizes the data and finds that Xbar=6.90 and S= 0.878. What sample size would the researcher need to use in order to decrease the margin of error of a 95% confidence interval to +-0.20 hours?

A random selection of volunteers at a research institute has been exposed to a weak flu virus. After the volunteers began to have flu symptoms, 20 of them were given multivitamin tablets daily that contained 1 gram of vitamin C and 3 grams of various other vitamins and minerals. The remaining 20 volunteers were given tablets containing 4 grams of vitamin C only. For each individual, the length of time taken to recover from the flu was recorded. At the end of the experiment the following data were obtained. Days to recover from flu Treated with 8.5, 5.6, 8.8. 6.1. 6.1. 3.3. 8.9, 6.0, 3.3, 9.7, 6.0, 9.3, 2.3, 4.6. 5.5.6.7. 6.6. 4.9. 10.0.6.6 multivitamin 6.5, 5.0, 3.2, 4.7, 3.5, 2.7, 3.8, 4.4, 4.6, 3.6, 4.0, 2.7, 3.2, 4.8, 6.3, 7.5, 6.9, 4.7, 4.8, 1.3 Treated with vitamin C Send data to calculator Send data to Excel Suppose that it is known that the population standard deviation of recovery time from the flu is 1.8 days when treated with multivitamins and that the population standard…

Bighorn sheep are beautiful wild animals found throughout the western United States. Let x be the age of a bighorn sheep (in years), and let y be the mortality rate (percent that die) for this age group. For example, x = 1, y = 14 means that 14% of the bighorn sheep between 1 and 2 years old died. A random sample of Arizona bighorn sheep gave the following information: x 1 2 3 4 5 y 15.8 17.3 14.4 19.6 20.0   Σx = 15; Σy = 87.1; Σx2 = 55; Σy2 = 1,540.45; Σxy = 272 (a) Find x, y, b, and the equation of the least-squares line. (Round your answers for x and y to two decimal places. Round your least-squares estimates to three decimal places.) x =   y =   b =   ŷ =   +   x

Do larger universities tend to have more property crime? University crime statistics are affected by a variety of factors. The surrounding community, accessibility given to outside visitors, and many other factors influence crime rate. Let x be a variable that represents student enrollment (in thousands) on a university campus, and let y be a variable that represents the number of burglaries in a year on the university campus. A random sample of n = 8 universities in California gave the following information about enrollments and annual burglary incidents. x 10.9 30.4 24.5 14.3 7.5 27.7 16.2 20.1 y 23 76 39 23 15 30 15 25   (a) Make a scatter diagram of the data. Then visualize the line you think best fits the data. A scatter diagram has a horizontal axis labeled "x (student enrollment (in thousands))" with values from 7.5 to 30.4 and a vertical axis labeled "y (annual number of burglaries)" with values from 15 to 76. The scatter diagram has 8 points. A pattern goes up and…

A transect is an archaeological study area that is  mile wide and 1 mile long. A site in a transect is the location of a significant archaeological find. Let x represent the number of sites per transect. In a section of Chaco Canyon, a large number of transects showed that x has a population variance . In a different section of Chaco Canyon, a random sample of 23 transects gave a sample variance  for the number of sites per transect. Use an  to test the claim that the variance in the new section is greater than 36.4.​ What is the level of significance?   90%   1%   5%   95%   10%

Two major automobile manufacturers have produced compact cars with engines of the same size. We are interested in determining whether or not there is a significant difference in the mean MPG (miles per gallon) when testing for the fuel efficiency of these two brands of automobiles. A random sample of eight cars from each manufacturer is selected, and eight drivers are selected to drive each automobile for a specified distance. The following data (in miles per gallon) show the results of the test. Assume the population of differences is normally distributed. Driver Manufacturer A Manufacturer B 1 36 30 2 31 31 3 30 28 4 30 27 5 29 27 6 33 30 7 35 25 8 29 31 The test statistic is 2.316. At  ? = 0.10,  the null hypothesis   should be revised .should not be tested.     should be rejected. should not be rejected.

Use the data and table below to test the indicated claim about the means of two paired populations (matched pairs). Assume that the two samples are each simple random samples selected from normally distributed populations. Make sure you identify all values.     The table below shows the blood glucose of 20 students before breakfast and two hours after breakfast, using a specific insulin dosing formula to cover carbohydrates. Is there compelling statistical evidence that the specific insulin dosing formula is effective in reducing blood glucose levels? Use a significance level of 0.05. We have the differences (gain or loss), but we still need to compute the mean, standard deviation, and know the sample size for the differences (use Excel or Sheets for this computation). Once those are found, we can apply methods that are used for a 1 sample t-test.     Student Before Meal After Meal Difference 1 161 114 -47 2 196 88 -108 3 132 80 -52 4 175 96 -79 5 169 112 -57 6 138 137…