An article on estimating 28-day strength of concrete considered regressing y 28-

Question

An article on estimating 28-day strength of concrete considered regressing y 28-day standard-cured strength (psi) against x- accelerated strength (psi). Suppose the equation of the true regression ine is y- 18101.1x. (a) What is the expected value of 28-day strength when accelerated strength 24107 psI (b) By how much can we expect 28-day strength to change when accelerated strength increases by 1 psi? psI (c) By how much can we expect 28-day strength to change when accelerated strength increases by 150 psi? PsI (d) By how much can we expect 28-day strength to change when accelerated strength decreases by 150 psi? psI

Explanation / Answer

in the equation y=1810+1.1x

a) if x=2410 then y=1810+1.1*2410=4461

b) if x increases by 1, the y will increase by 1.1

c) if x increases by 150, the y increases by 1.1*150=165

d) if x decreases by 150, then y decreases by 165

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.