LOTS OF POINTS IM DESPERATE! can someone please refresh my memory on a couple of log equations? Thank you!

78.  t=8.66yrs

79.  r=23.10%

80. r=11.0975%

Step-by-step explanation:

78. Given the initial deposit is $1,000 and the 8% compounded continuously. The doubling time can be calculated using the formula;

Given that A=2P, we substitute in the equation to solve for t:

Hence, it takes 8.66 years  for $1,000 to double in value.

79.

Given the initial deposit is $1,000 and the r% compounded continuously.

-The doubling rate can be calculated using the formula;

#We substitute our values in the equation to solve for r:

Hence, the deposit will double in 3 years at a rate of 23.10%

80.

Given the initial deposit is $30,000 and the future value is $2,540,689.

-Also, given t=40yrs, the rate of growth for continuous compounding is calculated as:

Hence, the deposit will grow at a rate of approximately 11.0975%

b.an increase in a causes b to decrease

yes. we do proportions in probabilities.