12 out of 50 seventh graders
said they would be willing to pay
between $21-$30 dollars for a
class trip. If there are 350
students in seventh grade,
about how many would go oh
the trip if it cost $30?

Why is the huronian supergroup rock formation particularly interesting to scientists? because it looks like a cross-section of a giant, stone encyclopedia because it formed during the period when oxygen began to accumulate in the atmosphere because it contains unusually large amounts of oxygen and sulfur because it dramatically altered the planet's development when it first formed