18. Why would researchers choose a double-blind study? O To prevent anyone from treating subjects in a way that changes their response

O To prevent researchers from knowing the results of a study after it is over

O To prevent subjects from choosing placebo

O Researchers do not use double-blind studies anymore

Add the fractions, and simply the result to lowest terms. 2/3 + 2/7= ?

Mikes car gets an average of 28 mpg. there are 12 gallons of fuel in mikes car when he starts his trip of 140 miles. about how many gallons are left at the end of his trip?

Nour and rana are shopping for a christmas tree. they are deciding between 2 22 different types of trees (real and fake) and 4 44 colors for the ornaments (white, silver, gold, and purple). they each created a display to represent the sample space of randomly picking a type of tree and a color for the ornaments. whose display correctly represents the sample space?