Answer by Mimiwhatsup: Convert the decimal numbers to a fraction by placing the decimal numbers over a power of ten. Since there are 13 numbers to the right of the decimal point, place the decimal numbers over 10^13 (10000000000000).

Answer:
Rate parameter of 
Step-by-step explanation:
Exponential distribution:
The exponential probability distribution, with mean m, is described by the following equation:
In which
is the decay parameter.
One appearance per two minutes.
This means that 
Measured in minutes, the time T until the next encounter is Exponential with what rate parameter?

So
Rate parameter of 
<span> 5.927 × 10<span>^-3 is your answer</span></span>
Standard deviation is calculated by the square root of the variance. Now, how do we solve the variance? The variance is the <span>average of the </span>squared differences from the Mean. Calculating the variance, we can obtain a standard deviation of <span>3.74. Therefore, the correct answer is option A.</span>