Question

7. Psychological and social factors can influence the survival of patients with serious diseases. One study compared the relationship between survival of patients with coronary heart disease and pet ownership. Patients were either classified as having a pet or not and whether they survived for 1 year. Based on the data below, is there an association between owning a pet and survival? No need to do the entire significance test, just the parts below. Pet Ownership Patient Status Yes No Alive 28 50 Dead 11 3 PM a. State the hypotheses for the appropriate test in the context of this problem. PM b. If the X test statistic has a value of 8.85 then give the p-value and conclusion of your significance test 8. A researcher wishes to determine whether the rate of water flow (x) (in liters per second) over an experimental soil bed can be used to predict the amount of soil washed away(y) (in kilograms). The researcher measures the amount of soil washed away for various flow rates, finds that the sample mean flow rate is 6. 11s with a standard deviation of 0.5 L/s. Also the sample mean for the amount of eroded soil is 4.2 kg with a standard deviation of 1.2 kg. If the correlation between flow rate (x) and the amount of eroded soil (y) is 0.65 then give The equation of the least squares regression line of yonx b. What is the prodicted amount of eroded soil for a flow rate or IL 9. The correlation between amount of time spent studying for a final and the final exam grade is 0.9. Explain what this means

Answer 1

a) Testing the null & alternative hypother Ho: There is no associath beth owning a pe & surrival. Vs Hi There is associath ben aurining a pet of survival b) chi-square test statistic x² = 8,85 df = (2-1) × CC-1) = (2-1) (3-1)=2 p-value = PC x2y8.85) = 0.0019 P-value = 0.0119 Conclusions p-value <0.05 Hence reject Ho. We conclude that the there is associath beth owning pet f survival. a let, the given as, The rate of flow (x) 2= 6.1 Sx=0.5 The amount of soil (7) y = 4.2 Sy=1.2 r= 0,65

al let, the slope is, Sx sy = 0.65 X 0.5 1.2 Bi = 0.2708 Intercept (Bo) is Boz 7- Bi = 4.2 - 0.2708 X 6.1 = 4,2-1.652 Bo= 2,5479 The least squame regression egg yonas is, } = Bot Bix y = 2,5479 + 0,2708 x b put x= 10 in the equation is, above regression h = 2.5479 +0,2708 x 10 = 5,2563 amount of eroded soil for a The

floco rate of the lols is 5.26 9). r=0.g. There is a perfect perfect positive comelath beth amount of time spent studying fora final & final exam score