Help please and thanks

Which best describes the strength of the correlation, and what is true about the causation between the variables? it is a weak negative correlation, and it is not likely causal. it is a weak negative correlation, and it is likely causal. it is a strong negative correlation, and it is not likely causal. it is a strong negative correlation, and it is likely causal.

The lengths of nails produced in a factory are normally distributed with a mean of 4.91 centimeters and a standard deviation of 0.05 centimeters. find the two lengths that separate the top 4% and the bottom 4%. these lengths could serve as limits used to identify which nails should be rejected. round your answer to the nearest hundredth, if necessary.

Suppose that the price p (in dollars) and the weekly sales x (in thousands of units) of a certain commodity satisfy the demand equation 4p cubedplusx squaredequals38 comma 400. determine the rate at which sales are changing at a time when xequals80, pequals20, and the price is falling at the rate of $.20 per week.