Answer:
c. $77.00
Explanation:
The CPI is 100 times the ratio of prices relative to those in some reference period. Here, we assume the reference year is 1983, so a CPI of 186 means the current prices are 1.86 times those in 1983.
1.86 × $41.40 = $77.00
The helment price will be $77.00 when the CPI is 186.