Question

A mixture of pulverized fuel ash and Portland cement to be used for grouting should have a compressive strength of more than 1300 KN/m^2. The mixture will not be used unless experimental evidence indicates conclusively that the strength specification has been met. Suppose compressive strength for specimens of this mixture is normally distributed with σ = 63. Let μ denote the true average compressive strength.
a. What are the appropriate null and alternative hypothesis?

Answer 1

Answer:

Null Hypothesis, $H_0$ : $\mu\leq$ 1300 KN/m^2

Alternate Hypothesis, $H_A$ : $\mu$ > 1300 KN/m^2

Step-by-step explanation:

We are given that a mixture of pulverized fuel ash and Portland cement to be used for grouting should have a compressive strength of more than 1300 KN/m^2.

Suppose compressive strength for specimens of this mixture is normally distributed with σ = 63.

Let $\mu$ = the true average compressive strength

So, Null Hypothesis, $H_0$ : $\mu\leq$ 1300 KN/m^2

Alternate Hypothesis, $H_A$ : $\mu$ > 1300 KN/m^2

Here, null hypothesis states that the compressive strength of pulverized fuel ash and Portland cement is less than or equal to 1300 KN/m^2.

On the other hand, alternate hypothesis sates that the compressive strength of pulverized fuel ash and Portland cement is more than 1300 KN/m^2.

So, this would be the appropriate null and alternative hypothesis.