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 line is y = 1830 + 1.3x.
(a) What is the expected value of 28-day strength when
accelerated strength = 2490?
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 130 psi?
psi
(d) By how much can we expect 28-day strength to change when
accelerated strength decreases by 130 psi?
psi
regression line is
y = 1830 + 1.3x
a)
for x = 2490
y = 1830 + 1.3*2490
y = 5067
b)
strenght to change by 1.3 psi
c)
if accelerated strength is increased by 130 psi
the strength increases by 1.3 * 130 = 169 psi
d)
if accelerated strength is decreased by 130 psi
the strength decreases by 1.3 * 130 = 169 psi
An article on estimating 28-day strength of concrete considered regressing y = 28-day standard-cured strength (psi)...
As Concrete cures, it gains strength. The following data
represent the 7-day and 28-day strength in psi of a certain type of
concrete. Conduct regression analysis for the following data and
comment on the coefficient of determination value. Calculate the
28th day strength for the concrete with seventh day strength of 4
psi
7-day 28-day strength, strength, X y 2,300 4,070 3,390 5,220 2,430 4,640 2,890 4,620 3,330 4,850 2,480 4,120 3,380 5,020 2,660 4,890 2,620 4,190 3,340 4,630
As concrete cures, it gains strength. The following data represent the 7-day and 28-day strength in pounds per square inch (psi) of a certain type of concrete. Complete parts (a) through (f) below. 7-Day Strength (psi), x 2300 2480 2620 2890 3330 28-Day Strength (psi), y 4070 4120 4190 4620 4850 OD. Ho: Bo = 0 Hy: Bo > 0 Determine the P-value of this hypothesis test. P-value = .006 (Round to three decimal places as needed.) What is the...
As concrete cures, it gains strength. The following data represent the 7-day and 28-day strength in pounds per square inch (psi) ofa certain type of concrete. Complete parts (a) through (f) below. 7-Dy Strength (psi)x 33802620 3390 2300 3330 4070 4850 28-Day Strength (psi,y 4190 (a) Treating the 7-day strength as the explanatory variable, use technology to determine the estimates of Po and pl P 1753.9 (Round to one decimal place as needed.) P sb9707 (Round to four decimal places...
A researcher wants to determine a model to predict the 28-day strength of a concrete mixture. The following data represent the slump (a measure of concrete uniformity in inches) x1, 7-day strength (in pounds per square inch, or psi) x2, and the 28-day strength (in psi) y of a certain type of concrete. Slump measure of the uniformity of the concrete, with a higher slump indicating a less uniform mixture. Complete parts (a) through (j). 3.75 4.5 2.5 4 3...
As concrete cures, it gains strength. The following data represent the 7-day and 28-day strength in pounds per square inch (psi) of a certain type of concrete. Complete parts (a) through (f) below. 7-Day Strength (psi), x 3340 3380 3330 2300 2480 28-Day Strength (psi), y 4630 5020 4850 4070 4120 (a) Treating the 7-day strength as the explanatory variable, x, use technology to determine the estimates of beta 0 and beta 1. beta 0almost equalsb 0equals nothing (Round to...
As concrete cures, it gains strength. The following data represent the 7-day and 28-day strength in pounds per square inch (psi) of a certain type of concrete. Complete parts (a) through (f) below. 7-Day Strength (psi), x 3340 3380 3330 2300 2480 28-Day Strength (psi), y 4630 5020 4850 4070 4120 (a) Treating the 7-day strength as the explanatory variable, x, use technology to determine the estimates of beta 0 and beta 1. beta 0almost equalsb 0equals nothing (Round to...
I NEED A SOLUUTION ASAP
consider the situation where x-accelerated strength o concrete and y 28 day cured strength. Suppose the simple linear regression model s valid for x between 100 and 4000 and that experiment in which n-7, and the x values at which observations are mede are x1-800.x2 = 1 700.x3-2200, x4 = 2600, x5 = 3200, x5-3600, and x7-3800. 1 25 and σ 3 Consider an 1 (a) Calculate o, the standard deviation of F (Round your...
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