Problem 6-23 (Algorithmic) The medical community unanimously agrees on the healt
ID: 3065354 • Letter: P
Question
Problem 6-23 (Algorithmic) The medical community unanimously agrees on the health benefits of regular exercise, but are adults listening? During each of the past 15 years, a polling organization has surveyed americans about their exercise habits. In the most recent of these polls, slightly over half of all American adults reported that they exercise for 30 or more minutes at least three times per week. The following data show the percentages of adults who reported that they exercise for 30 or more minutes at least three times per week during each of the 15 years of this study. Percentage of Adults Who Exercise 30 or more minutes at least three times per week
(Year1) 41.1
(Year2) 45
(Year3) 47.2
(Year4) 45.6
(Year5) 46.5
(Year6) 44.4
(Year7) 47.7
(Year8) 49.9
(Year9) 48
(Year10) 49
(Year11) 50
(Year12) 52.2
(Year13) 50.7
(Year14) 54.5
(Year15) 52.3
B. use simple linear regression to find the parameters for the line that minimizes MSE for this time series. Do not round your interim computations and round your final answers to four decimal places. For subtractive or negative numbers use a minus sign. (Example: -300)
y-intercept, b0 =
Slope, b1 =
MSE =
C. Use the trend equation from part (b) to forecast the percentage of adults next year (year 16 of the study) who will report that they exercise for 30 or more minutes at least three times per week. Do not round your interim computations and round your final answers to four decimal places. For subtractive or negative numbers use a minus sign. (Example: -300) %
D. Use the trend equation from part (b) to forecast the percentage of adults three years from now (year 18 of the study) who will report that they exercise for 30 or more minutes at least three times per week. Do not round your interim computations and round your final answers to four decimal places. For subtractive or negative numbers use a minus sign. (Example: -300)
Explanation / Answer
b)
y-intercept, b0 =42.579047
Slope, b1 =0.7117857
MSE =1.509213
c)
y^ = 42.579047 + 0.711785 * x
when x = 16
y^= 42.579047 + 0.711785*16
= 53.967607
d)
when x = 18
y^= 42.579047 + 0.711785*18
=55.391177
SUMMARY OUTPUT Regression Statistics Multiple R 0.90956775 R Square 0.827313492 Adjusted R Square 0.814029914 Standard Error 1.509213766 Observations 15 ANOVA df SS MS F Significance F Regression 1 141.8588929 141.8588929 62.28092448 2.59476E-06 Residual 13 29.61044048 2.27772619 Total 14 171.4693333 Coefficients Standard Error t Stat P-value Lower 95% Intercept 42.57904762 0.820043622 51.92290566 1.84041E-16 40.80745108 t 0.711785714 0.090192774 7.891826435 2.59476E-06 0.516936073