Mathematics, 21.12.2019 05:31, pinsonjon1129
An article in concrete research ["near surface characteristics of concrete: intrinsic permeability" (1989, vol. 41)] presented data on compressive strength x and intrinsic permeability y of various concrete mixes and cures. summary quantities are n = 14,
∑yi=572,∑y2i=23,530,∑xi=43,∑x2i=157 .42and∑xiyi=1697.80
. assume that the two variables are related according to the simple linear regression model. a. calculate the least squares estimates of the slope and intercept. estimate σ². graph the regression line. b. use the equation of the fitted line to predict what permeability would be observed when the compressive strength is x = 4.3. c. give a point estimate of the mean permeability when compressive strength is x = 3.7. d. suppose that the observed value of permeability at x = 3.7 is y = 46.1. calculate the value of the corresponding residual.
Answers: 1
Mathematics, 21.06.2019 19:20, alexcarrasco5903
1- is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis. 2- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis. 3- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in part b?
Answers: 3
Mathematics, 21.06.2019 21:30, happysage12
Every weekday, mr. jones bikes from his home to his job. sometimes he rides along two roads, the long route that is shown by the solid lines. other times, he takes the shortcut shown by the dashed line. how many fewer kilometers does mr. jones bike when he takes the shortcut instead of the long route?
Answers: 1
An article in concrete research ["near surface characteristics of concrete: intrinsic permeability"...
History, 24.10.2019 07:43
Physics, 24.10.2019 07:43
Mathematics, 24.10.2019 07:43
Chemistry, 24.10.2019 07:43