Question

Dalia owns a gravel pit. She took a random sample of rocks and counted 585858 sedimentary rocks, 213213213 metamorphic rocks, and 522522522 igneous rocks. Use the observed frequencies to create a probability model for Dalia randomly selecting one rock from her gravel pit. Input your answers as fractions or as decimals rounded to the nearest hundredth. Type of rock Estimated probability Sedimentary Metamorphic Igneous

Answer 1

step One

Find the total number of rocks in the gravel pit

58 + 213 + 522 = 793

Step Two 

Set up the probabilities.

P(Sedimentary) = 58 / 793 = 0.0731

P(metamorphic) = 213/ 793 =0.2686

P(igneous) =        522 / 793 = 0.6583

Check

When these are added together the answer should be one.

0.0731 + 0.2686 + 0.6583 = 1 just as it should.