Astudy of the relationship between age and various visual functions (such as acuity and depth perception) reported the following observations on the area of scleral lamina (mm2) from human optic nerve heads: 2.79 2.57 2.73 3.75 2.27 2.75 4.00 4.22 3.88 4.35 3.41 4.57 2.38 3.73 2.75 3.47 3.06(a) calculate ? xi and ? xi2. (round ? xi2 to two decimal ) use the values calculated in part (a) to compute the sample variance s2 and then the sample standard deviation s. (round your answers to three decimal places.)

Ill mark the brainliest if you me with the these three questions 7,8,9

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.

Which of the following choices gives you a slope of 3?