A new-car dealer is leasing various brand-new models for the monthly rates (in dollars) listed below. Estimate

Question:

A new-car is leasing various brand-new models for the monthly rates (in dollars) listed below. Estimate the true population variance (and standard deviation) in leasing rates with 90% confidence.
169 169 199 239 239 249 Dealer
A dealer in the securities market is an individual or firm who stands ready and willing to buy a security for its own account (at its bid price) or sell from its own account (at its ask price). A dealer seeks to profit from the spread between the...