The correct answer is Choice B: 0.3098.
To find the answer, you have to use a normal distribution table. Look up the percents for each z-score and subtract them to find the region between.
z = 1.92 the percent is 0.9726
z = 0.42 the percent is 0.6628
0.9726 - 0.6628 = 0.3098
Answer:
The mean of the combined math and verbal scores is 1100, while the standard deviation is 141.
Step-by-step explanation:
Normal variables
Normal variables have mean and standard deviation
When we add normal variables, the combined mean is the sum of both means, and the standard deviation is the square root of the sum of both variances. The distribution is still normal.
In this question:
Verbal: .
Math:
Combined:
The mean of the combined math and verbal scores is 1100, while the standard deviation is 141.
Answer:
x = -2.5
Step-by-step explanation:
Step 1: Write equation
-6.2 - 12.6x = 5.8 - 7.8x
Step 2: Solve for <em>x</em>
<u>Add 12.6x on both sides:</u> -6.2 = 5.8 + 4.8x
<u>Subtract 5.8 on both sides:</u> -12 = 4.8x
<u>Divide both sides by 4.8:</u> x = -2.5
Step 3: Check
<em>Plug in x to verify if it's a solution.</em>
-6.2 - 12.6(-2.5) = 5.8 - 7.8(-2.5)
-6.2 + 31.5 = 5.8 + 19.5
25.3 = 25.3
True. An invalid statistical test measure may have questions that are misinterpreted.