You and your friend each start a car-washing service. You spend $25 on supplies and charge $10 per car. Your friend spends $55 on supplies and charges $13 per car. How many cars do you have to wash to earn the same amount of money as your friend?
y = 10x - 25 y = 13x - 55
? cars​

Now, martin can reasonably guess that the standard deviation for the entire population of people at the mall during the time of the survey is $1.50. what is the 95% confidence interval about the sample mean? interpret what this means in the context of the situation where 95 people were surveyed and the sample mean is $8. use the information in this resource to construct the confidence interval.