1. commonly used measure of inflation is the annual rate of change of the Consumer Price Index (CPI). A TV new story says that the annual rate of change of the CPI is increasing.

Check all of the following that must be true.

Group of answer choices

The graph of CPI is concave upward.

The derivative of CPI is positive.

The derivative of CPI is negative.

The second derivative of CPI is negative.

The second derivative of CPI is positive.

The graph of CPI is concave downward.

2.

Diminishing Returns

Jesaki Inc estimates that it will sell N(x) units of product after spending $x thousand on advertising, as given by

N(x)= 0.6 x4+ 50 x3 1,067 x2+ 164,190.

What is the point of diminishing returns? Round to the nearest dollar.

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