Sovi.AI - AI Math Tutor

Scan to solve math questions

QUESTION IMAGE

find the equation of the regression line for the given data. then const…

Question

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 table below shows the heights (in feet) and the number of stories of six notable buildings in a city.\
height, x\
stories, y\
768\
52\
628\
48\
518\
45\
511\
43\
491\
39\
478\
38\
(a) x = 499 feet\
(b) predict the value of y for x = 641. choose the correct answer below.\
a. 41\
b. 48\
c. 33\
d. not meaningful\
(c) predict the value of y for x = 318. choose the correct answer below.\
a. 33\
b. 48\
c. 33\
d. not meaningful\
(d) predict the value of y for x = 732. choose the correct answer below.\
a. 41\
b. 52\
c. 33\
d. not meaningful

Explanation:

First, we calculate the regression line equation for the given data (x: height, y: stories):
Data points: (499,38), (491,39), (511,43), (518,45), (628,48), (768,52)

Step1: Compute means

$\bar{x} = \frac{499+491+511+518+628+768}{6} = \frac{3415}{6} \approx 569.17$
$\bar{y} = \frac{38+39+43+45+48+52}{6} = \frac{265}{6} \approx 44.17$

Step2: Calculate slope (b)

Using formula $b = \frac{\sum (x_i - \bar{x})(y_i - \bar{y})}{\sum (x_i - \bar{x})^2}$
After calculation, $b \approx 0.0426$

Step3: Calculate intercept (a)

$a = \bar{y} - b\bar{x} \approx 44.17 - 0.0426(569.17) \approx 19.8$

Regression equation: $\hat{y} = 19.8 + 0.0426x$

Predictions:

(a) $x=499$: $\hat{y} \approx 19.8 + 0.0426(499) \approx 39.1 \approx 39$ (closest to 38, but options not shown—assuming context aligns with given choices for other parts)
(b) $x=641$: $\hat{y} \approx 19.8 + 0.0426(641) \approx 19.8 + 27.3 \approx 47.1 \approx 48$ → B
(c) $x=318$: Outside the range of x-values (491-768) → extrapolation, not meaningful → D
(d) $x=732$: Outside the range of x-values → extrapolation, not meaningful → D

Answer:

(b) B. 48
(c) D. not meaningful
(d) D. not meaningful

(Note: For part (a), since options are not provided in the visible prompt, we focus on the parts with clear options as per the image.)