Problem: A car salesperson receives a 12% commission of the sales price of the car for each car he sells in addition to his weekly salary of $1,350. Last week he sold a car for $29,999. What was his total paycheck for the week?

The average is about $800

Step-by-step explanation:

Most dealers pay their salespeople a 25% commission rate, which is based on gross profit minus a “pack” fee. Pack is usually a few hundred dollars ($800) but can also be a percentage. Example: You sell a used car for $3000 over cost

whenever we increase level of confidence for the same sample size we find that confidence interval becomes wider.

Step-by-step explanation:

Given that a random sample of size n  is drawn from a population that is known to be normally distributed. The sample variance, s2, is determined to be 19.8

Std error of sample would be = for n =25

Margin of error = critical value * std error

a) Here n <30.  (95%)So we use t critical value for df 9 is used for confidence interval

t critical = 2.262

95% confidence interval =[

b) Here n <30.  (95%) So t critical for df 24 is used.

t critical = 2.065

Confidence interval = (17.962, 21.638)

c) For 99% t critical for df 9 is used.

t critical=3.250

Std error = 1.483

confidence interval = (14.980, 24.620)

a) whenever we increase level of confidence for the same sample size we find that confidence interval becomes wider.

Similarly for the same confidence level, if sample size is increases, confidence interval becomes narrower.