Polymer composite materials have gained popularity because they have high strength-to-weight ratios and are relatively easy and inexpensive to manufacture. However, their nondegradable nature has prompted the development of environmentally friendly composites using natural materials. An article reported that for a sample of 10 specimens with 2% fiber content, the sample mean tensile strength (MPa) was 51.6 and the sample standard deviation was 1.2. Suppose the true average strength for 0% fibers (pure cellulose) is known to be 48 MPa. Does the data provide compelling evidence for concluding that the true average strength for the WSF/cellulose composite exceeds this value? (Use ̑ = 0.05)
State the appropriate hypotheses:
H0: ̑ = 48
Ha: ̑ > 48
Calculate the test statistic and determine the p-value: (Round your test statistic to two decimal places and your p-value to three decimal places)
t =
p-value =
What can you conclude?
The data provides compelling evidence that the true average strength for the WSF/cellulose composite exceeds 48.
The data does not provide compelling evidence that the true average strength for the WSF/cellulose composite exceeds 48.