Question

A random sample of ten 2011 sports cars is taken and their city mileage is recorded. The results are as follows: 20 21 25 21 21 23 31 32 28 26 Assuming the population distribution is normal, compute E, the margin of error for the t interval, for a 90% confidence interval for m, the population mean of the city mpg for 2011 sports cars. Question 7 options: a.) 2.531 b.) 3.546 c.) 1.843 d.) 4.128

Answer 1

Here ,

Margin of error =

Where , s is standard error .

n : Number of observation .

   is critical value .

Now , Here n=10 .

And 90% confidence interval is given .

That means

Now ,

   ...................From statistical table

Standard error is given by ,

Where Xi is the ith observation and is the mean .

Now

Margin Of Error = =

Therefore , Option (a) is correct .