Question

An ecologist is concerned that the number of toads that inhabit an area is declining. Since it is difficult to count the total number of toads exactly, a method that they use to detect the abundance of toads is to measure the time between mating calls during mating season. From a ten-year-old study, the mean time between mating calls was 1.2 seconds with a standard deviation of .3 seconds. Let X denote the random time between mating calls of these toads, and suppose X is normally distributed. The ecologist randomly selects a time between mating calls. Please compute the values up to three decimals ( ex: 0.571) Calculate the probability that the selected time is exactly 1.2 seconds

Answer 1

0% probability that the selected time is exactly 1.2 seconds.

Explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean
`\mu` and standard deviation
`\sigma`, the z-score of a measure X is given by:

`Z = (X - \mu)/(\sigma)`

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

The probability of a value being equals to x is 0 in the normal distribution.

From a ten-year-old study, the mean time between mating calls was 1.2 seconds with a standard deviation of .3 seconds.

This means that
`\mu = 1.2, \sigma = 0.3`

Calculate the probability that the selected time is exactly 1.2 seconds?

In the normal distribution, the probability of a finding an exact value is 0. So 0% probability that the selected time is exactly 1.2 seconds.