A perfect straight line sloping downward would produce a correlation coefficient equal to:
A. \(- 1\)
B. \( - 2 \)
C. \( + 2 \)
D. \( + 1 \)
Generally speaking, if two variables are unrelated (as one increases, the other shows no pattern), the covariance will be:
A. a positive or negative number close to.zero
B. a large positive number
C. a large negative number
D. none of the above
Find the solution of the exponential equation \( 16 e ^ { x } = 12 \) in terms of logarithms, or correct to four decimal places. \( x = \)
Certain radioactive material decays in such a way that the mass remaining after \( t \) years is given by the function
\( m ( t ) = 100 e ^ { - 0.01 t } \)
where \( m ( t ) \) is measured in grams. (a) Find the mass at time \( t = 0 \) . Your answer is (b) How much of the mass remains after \( 20 \) years? Your answer is Round answers to \( 1 \) decimal place.
