Consider a population of Pacific tree frogs (Pseudacris regilla). In this population of frogs, a single locus controls the production of a mating call. This locus has two alleles - S1 and S2. You observe the following genotype counts:

S1S1 = 987

S1S2 = 333

S2S2 = 21

Use these data to calculate the chi-square statistic. Report your calculated chi-square statistic to two decimal places.