Question

A wildlife preserve features a crocodile with a documented age of 24 years, believed to be one of the oldest crocodiles in captivity. The lifespans of crocodiles have an approximately Normal distribution, with a mean of 18 years and a standard deviation of 2.6 years. What proportion of crocodiles have lifespans of at least 24 years? Find the z-table here. O 0.0104 O 0.3336 O 0.4896 O 0.6664​

Answer 1

Answer:

0.0104

Step-by-step explanation:

Given that, the lifespans of crocodiles have an approximately Normal distribution, with a mean of 18 years and a standard deviation of 2.6 years.

So, mean, $\mu=18$

and standard deviation, $\sigma=2.6$

The z-score, for any arbitrary life span of  x year, is given by

$z=\frac{x-\mu}{\sigma}$

By using the given values, we have

$z=\frac{x-18}{2.6} \cdots(i)$

The z-score for x=24, by using equation (i), is

$z=\frac{24-18}{2.6}=\frac{6}{2.6}=2.31$

From the table, the area to the left side of z=2.31 =0.98956

But, the proportion of crocodiles have lifespans of at least 24 years

= Area to the right side of the z=2.31

=1- (Area to the left side of the z=2.31)

=1-0.98956

=0.01044

So, the proportion of crocodiles that have lifespans of at least 24 years is 0.0104.

Hence, option (a) is correct.

Answer 2

Answer:

A

Step-by-step explanation: