The consumer price index for planet econ consists of only two items: books andhamburgers. in 2010, the base year, the typical consumer purchased 10 books for$25 each and 25 hamburgers for $2 each. in 2015, the typical consumer purchased15 books for $30 each and 30 hamburgers for $3 each. the consumer price indexfor 2015 on planet econ equals:

The consumer price index for 2015 on Planet Econ is 1.25

Explanation:

The formula for computing the consumer price index is given below:

= (Total cost in the current year) ÷ (total cost in the base year)

where,

Total cost in the current year equals to

= (Base year book quantity × current year book price) + (base year hamburgers quantity × current year hamburgers price)

= 10 books × $30 + 25 hamburgers × $3

= $300 + $75

= $375

we use the base year quantity for computing the total cost for the current year.

And, the Total cost in the base year equals to

= (Base year book quantity × base year book price) + (base year hamburgers quantity × base year hamburgers price)

= 10 books × $25 + 25 hamburgers × $2

= $250 + $50

= $300

Now put these values to the above formula

So, the answer would be

= $375 ÷ $300

= 1.25

Hence, The consumer price index for 2015 on Planet Econ is 1.25

the assumption the narrator makes in this excerpt is that the messages he heards were going to hurt the narrator's mom; the narrator just springs in to action. the narrator doesn't specify in this excerpt why he believes that the messages present a problem that requires protection.