Bob is trying to decide between two cell phone plans. Plan A has no flat fee, but the user must pay $10 cents per minute on the
phone. Plan B requires a one-time fee of $20 but only requires a payment of $5 cents per minute on the phone. What is the minimum whole number of minutes Bob has to use the phone for to make Plan B the cheaper plan? PLZ HELP ASAP
Thanks
Let x be the number of minutes that Bob anticipates using. Plan A costs 10x cents, while Plan B costs 2000 + 5x cents. We therefore have the inequality
2000+5x < 10x
2000 < 5x
400 < x.
The smallest integer x such that 400 < x is 401. Therefore, Bob must use at least <u>401</u> minutes to make Plan B cheaper.
This is not an experiment because no treatment is being imposed upon the customers. Additionally, this study used a stratified sample because independent random samples were selected from two distinct populations of customers.