In: Math
pediatrician wants to determine the relation that may exist between a child's height and head circumference. She randomly selects 5 children and measures their height and head circumference. The data are summarized below. Complete parts (a) through (f) below. Height (inches), x 27 25.5 27.75 25 26.5 Head Circumference (inches), y 17.5 17.1 17.6 16.9 17.3 (a) Treating height as the explanatory variable, x, use technology to determine the estimates of beta 0 and beta 1. beta 0 almost equalsb 0 equals ???????? (Round to four decimal places as needed.) beta 1almost equalsb 1equals nothing (Round to four decimal places as needed.) (b) Use technology to compute the standard error of the estimate, s Subscript e. s Subscript eequals ????(Round to four decimal places as needed.) (c) A normal probability plot suggests that the residuals are normally distributed. Use technology to determine s Subscript b 1. s Subscript b 1equals ?????? (Round to four decimal places as needed.) (d) A normal probability plot suggests that the residuals are normally distributed. Test whether a linear relation exists between height and head circumference at the alphaequals0.01 level of significance. State the null and alternative hypotheses for this test. Choose the correct answer below. A. Upper H 0: beta 0equals0 Upper H 1: beta 0not equals0 B. Upper H 0: beta 0equals0 Upper H 1: beta 0greater than0 C. Upper H 0: beta 1equals0 Upper H 1: beta 1not equals0 Your answer is correct.D. Upper H 0: beta 1equals0 Upper H 1: beta 1greater than0 Determine the P-value for this hypothesis test. P-valueequals ????? (Round to three decimal places as needed.) What is the conclusion that can be drawn? A. Do not reject Upper H 0 and conclude that a linear relation does not exist between a child's height and head circumference at the level of significance alphaequals0.01. B. Reject Upper H 0 and conclude that a linear relation does not exist between a child's height and head circumference at the level of significance alphaequals0.01. C. Do not reject Upper H 0 and conclude that a linear relation exists between a child's height and head circumference at the level of significance alphaequals0.01. D. Reject Upper H 0 and conclude that a linear relation exists between a child's height and head circumference at the level of significance alphaequals0.01. (e) Use technology to construct a 95% confidence interval about the slope of the true least-squares regression line. Lower bound: ???? Upper bound: ????? (Round to three decimal places as needed.) (f) Suppose a child has a height of 26.5 inches. What would be a good guess for the child's head circumference? A good estimate of the child's head circumference would be ???????? (Round to two decimal places as needed.)
I used r software to solve this problem,
R codes
x=c(27,25.5,27.75,25,26.5)
y=c(17.5,17.1,17.6,16.9,17.3)
fit=lm(y~x)
summary(fit)
Call:
lm(formula = y ~ x)
Residuals:
1 2 3 4 5
0.05455 0.03636 -0.03636 -0.03636 -0.01818
Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) 10.57273 0.58355 18.12 0.000367 ***
x 0.25455 0.02213 11.50 0.001411 **
---
Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
Residual standard error: 0.04924 on 3 degrees of freedom
Multiple R-squared: 0.9778, Adjusted R-squared: 0.9704
F-statistic: 132.3 on 1 and 3 DF, p-value: 0.001411
> confint(fit)
2.5 % 97.5 %
(Intercept) 8.7156220 12.4298326
x 0.1841173 0.3249736