Define design confound. How do design confounds threaten validity? What type of validity is at risk with design confounds? When do problems in a study become confounds?

Michael is training for a marathon. in his first week he plans to run 8miles. what path should he take

Which expressions are equivalent to -7+3(-4e-3)? choose all answers that apply: choose all answers that apply: a -4(3e+4)? 4(3e+4) b 12e12e c none of the above

Points j and k plotted on the coordinate grid are two vertices of rectangle jklm rectangle jklm has an area of 7 square units point j is located at 2,1 and point k is located at -5,1 each vertex of the rectangle is located at a point that has integer coordinates. what is the perimeter of rectangle jklm? (need answer asap)