2. Scientists estimate that the distribution of the life span of the Galápagos Islands giant tortoise is
approximately normal with mean 100 years and standard deviation 15 years. Based on the estimate, which
of the following is closest to the age of a Galápagos Islands giant tortoise at the 90th percentile of the
distribution?

Using the normal distribution, it is found that an age of 119 years is closest to the 90th percentile.

-------------------

Normal Probability Distribution

The z-score formula is used, which, in a set with mean and standard deviation , is given by:  

-------------------

Thus:

An age of 119 years is closest to the 90th percentile.

A similar problem is given at link

119.2

Step-by-step explanation:

Given the following :

Mean (m) = 100 years

Standard deviation (sd) = 15 years

closest to the age of a Galápagos Islands giant tortoise at the 90th percentile of the

distribution?

Obtain the Zscore for 90th percentile (0.90) on the z table = 1.28

Zscore = (X - mean) / standard deviation

1.28 = (X - 100) / 15

1.28 × 15 = X - 100

19.2 = X - 100

19.2 + 100 = X

X = 119.2

homozygous. one is homozygous, while two is heterozygous.