Images Horsepower
275
300
terextr35 (34K) 350
365
400
terextr45 (32K) 525
terextr60 (22K) 650
terextr70 (24K) 760
terextr100 (46K) 1050
terexurtruck (58K) 1775

Use the horsepower data to perform the following calculations:

  1. _______ Find the sample size n
  2. _______ Find the minimum horsepower
  3. _______ Find the maximum horsepower
  4. _______ Find the range of the horsepower
  5. _______ If this data is to be divided into four bins what is the width of a single bin?
  6. Determine the frequency and calculate the relative frequency using four bins.
    Bins (x)Frequency (f)P(x)
    _____________________
    _____________________
    _____________________
    _____________________
    Sum: _______________ _______________
  7. Construct a 95% confidence interval for the mean horsepower.
    1. __________ What is the point estimate for the population mean ?
    2. df = _________ How many degrees of freedom?
    3. tc = _________ What is tc?
    4. The error tolerance E = ____________
    5. The 95% confidence interval for the mean horsepower is _______ ≤ ≤ _______
Confidence interval statistics
Degrees of freedom df = n-1 =COUNT(data)-1
Find a zc value from a confidence level c zc =ABS(NORMSINV((1-c)/2))
Find a tc value from a confidence level c tc =TINV(1-c,df)
Calculate an error tolerance E of a mean for any n using sx. E error_tolerance_tc.gif (989 bytes) =tc*sx/SQRT(n)
Calculate a confidence interval for a population mean µ from a sample mean x and an error tolerance E x-E≤ ≤x+E