Which of the following is true of a linear regression line? a.  Located as close as possible to all the points of a scatter chart. B.  Is defined by an equation having 2 parameters: the slope and the intercept c.  Provides an approximate relationship between the values of two parameters d.  All of the above

Arsenic is a compound that occurs naturally in very low concentrations. Arsenic blood concentrations in healthy individuals are Normally distributed with a mean of 3.2 mg/dl. Some areas of the United States have naturally elevated arsenic levels in the ground and water supplies. Researchers took a sample 20 water samples from a particular area and measured the arsenic levels in each of the 20 water samples. They want to determine if there is sufficient evidence to conclude that the arsenic level in that area is higher than 3.2 mg/dl. hypothesis test for one population mean (unknown population standard deviation) confidence interval estimate for one population mean (unknown population standard deviation) hypothesis test for population mean from paired differences confidence interval estimate for population mean from paired differences hypothesis test for difference in population means from two independent samples confidence interval estimate for difference in population means from two…

Find the equation of the regression line for the given data. Then construct a scatter plot of the data and draw the regression line. (The pair of variables have a significant correlation.) Then use the regression equation to predict the value of y for each of the given x-values, if meaningful. The number of hours 6 students spent for a test and their scores on that test are shown below. Hours spent studying, x 0 Test score, y 38 Find the regression equation. 2 3 3 4 6 45 50 49 61 68 0 (a) x = 2 hours (c) x = 15 hours (b)x=4.5 hours (d) x=2.5 hours y = X + (Round the slope to three decimal places as needed. Round the y-intercept to two decimal places as needed.)

A researcher is interested in seeing if there is a relationship the amount of time in minutes a person spends in their car during the day and the number of minutes that person spends listening to music.   Car Time 63 14 241 93 140 3 91 45 22 Music Time 73 16 260 142 206 31 78 47 29   a. Find the equation of the regression line and use it to make a prediction of the dollars purchased by someone who visits the website 4 times.b. Interpret the slope in the context of the problem.c. Interpret the y-intercept in the context of the problem or state why it is not applicable.d. State the null and alternative hypotheses for the hypothesis test of correlation e. Find the pvalue and state your conclusion in the context of the study.

researcher would like to examine the effect of fertilizer on flower growth. She obtains several flowers. She randomly assigns half the plants to the no fertilizer condition. The other half of the plants receive fertilizer. She monitors their growth for a month. She then compares the amount of growth of the two sets of plants. Is there a difference in growth between the no fertilizer and the fertilizer conditions? Use the .05 level of significance. In addition, find Cohen’s d and state what the effect size is in a sentence. Growth Rating No Fertilizer 40,21,27,30, 47 Fertilizer 46,25, 24, 38, 53

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Find the slope (b1) for the regression equation for the following values. Round to 3 decimal places.    Define Variables xi yi 33 180 25 170 50 200 65 186 57 160 27 165

In order for applicants to work for the foreign-service department, they must take a test in the language of the country where they plan to work. The data below shows the relationship between the number of years that applicants have studied a particular language and the grades they received on the proficiency exam. Find the equation of the regression line for the given data. Number of years, x 4 4 3 6 2 7 3 Grades on test, y 61 68 75 82 73 90 58 93 72 滷 O A. =6.910x+46.261 O B. y = 46.261x+6.910 OC. v=6.910x-46.261 OD. O D. y = 46.261x -6.910 Fi St 5e Assig

Different hotels in a certain area are randomly selected, and their ratings and prices were obtained online. Using technology, with x representing the ratings and y representing price, we find that the regression equation has a slope of 135 and a y-intercept of -373. Complete parts (a) and (b) below. a. What is the equation of the regression line? Select the correct choice below and fill in the answer boxes to complete your choice. O A. y=] + ()& OB. -+x O D. y=+ ()× b. What does the symbol y represent? O A. The symbol y represents the average price of hotels in the area O B. The symbol y represents the expected price when the hotel's rating is 0. O C. The symbol y represents the predicted value of price. O D. The symbol y represents the amount that price increases with a 1-point increase in rating.

Different hotels in a certain area are randomly selected, and their ratings and prices were obtained online. Using technology, with x representing the ratings and y representing price, we find that the regression equation has a slope of 120 and a y-intercept of - 369. Complete parts (a) and (b) below. a. What is the equation of the regression line? Select the correct choice below and fill in the answer boxes to complete your choice. O A. A. V= O B. y = O C. ý= O D. y =