For the plant which manufactures bars of steel, the conclusions are as follows;
A. The scatter graph is shown.
B. The equation is y = 2.204 + 1.007x
C. Null hypotheses (H₀); β = 0
Alternative hypotheses (Hₐ); β ≠ 0
D. P-value (0.0001) is less than the significance level (α = 0.05).
What are null hypotheses and alternative hypotheses?
In null hypotheses, there is no relationship between the two phenomenons under the assumption or it is not associated with the group. And in alternative hypotheses, there is a relationship between the two chosen unknowns.
At a plant that manufactures bars of steel, a machine is used to cut the bars to specific lengths.
The machine has a dial that sets the length of the bars to be cut.
The dial is currently out of alignment and the plant manager is collecting data to assess the situation.
The following table shows 8 trials at different dial settings along with the actual output length of the bars that were cut.
All measurements are in millimeters.
Dail setting Output length
75 78
77 79
79 82
80 83
81 85
82 83
83 86
85 88
A. The scatter plot is shown below.
Based on the scatter plot, a linear model seems appropriate to the model relationships between the dial setting of the machine and the output length of the steel bar.
The scatter plot shows the strong (r = 0.965), positive, linear association. There do not appear to be any outliners.
B. From the data to construct a least-squares regression line to predict output length from dial setting. Then
y = (a + bx)
Let x be the dial setting machine and y be the output length of steel bars (in mm).
y = 2.204 + 1.007 x
C. All conditions for inference are met. Indicate the hypotheses appropriate to test whether there is a linear relationship between output length and dial setting.
Let β be the true slope of the population regression line relating the dial setting of the machine (x) and the output length of the steel bars (y) at the manufacturing plant.
Null hypotheses (H₀) ; β = 0
Alternative hypotheses (Hₐ) ; β ≠ 0
Appropriate test = slope of regression line t-test.
D. The test statistic for the appropriate test is t = 9.018 with 6 degrees of freedom (7 - 1)
The normal curve is shown;
Using calculator command t-CDF, with the alternative hypotheses as β≠0, then P-value = 0.0001.
In probability notation;
P(b≥0.017) = P(t≥9.018) = 0.00005
P-value = (2) × (0.00005) = 0.0001
P-value = 0.0001
Assume α = 0.05
Since our P-value (0.0001) is less than the significance level (α = 0.05), we do not convince statistical evidence that there is a linear relationship between output length and dial setting.
As the dial setting (x) increases, the output length of the steel bar (y) increases as well.
More about the null hypotheses and alternative hypotheses link is given below.
https://brainly.com/question/9504281
