Final answer:
To calculate the 99% lower confidence bound for the true average ultimate tensile strength, subtract the product of Z-score and standard deviation from the mean.
Step-by-step explanation:
To calculate a 99% lower confidence bound for the true average ultimate tensile strength, you can use the formula:
Lower Confidence Bound = Mean - (Z * (Standard Deviation / Square Root of Sample Size))
Using the given descriptive statistics, the formula would be:
Lower Confidence Bound = 135.39 - (2.33 * (4.59 / Square Root of 153))
Calculating the value, the lower confidence bound for the true average ultimate tensile strength is approximately 134.27. This means you can be 99% confident that the true average ultimate tensile strength is at least 134.27.