X = 15
X + 90 = 7x
X = 7x - 90
X - 7x = -90
-6x = 90
Divide both sides by -6
X = 15
Answer:
The 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 is (-8.04, 0.84).
Step-by-step explanation:
The (1 - <em>α</em>)% confidence interval for the difference between population means is:

The information provided is as follows:

The critical value of <em>z</em> for 98% confidence level is,

Compute the 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 as follows:


Thus, the 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 is (-8.04, 0.84).
Latus rectum is the line segment that passes through the focus, is perpendicular to the axis, and has both endpoints on the curve.
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The <span>x-intercept </span>indicates that the entire pile of dirt will have been moved after 6 hours.