Answer:
6
Step-by-step explanation:
Answer:
the common difference is 6.
Step-by-step explanation:
Given;
first term of an AP, a = -7
let the common difference = d
The third term is written as;
T₃ = a + 2d
The eight term is written as;
T₈ = a + 7d
The ratio of the eight term to third term = 7:1

Therefore, the common difference is 6.
Answer:
9,000
Step-by-step explanation:
If x < 5, we round down.
If x ≥ 5, we round up.
Since 8,503, 500 is ≥ 5, we round up to 9. So,
8,503 ≈ 9,000
The z-score of a person who scored 128 on the exam is equal to 2.9
<h3>What is a
z-score?</h3>
A z-score is also referred to as a z-value or standard score and it can be defined as a measure of the distance between a raw score and the mean, when standard deviation units are used.
Mathematically, the z-score of a given sample score in a normal distribution can be calculated by using this formula:

Where:
- x represents the sample score.
- u represents the mean score.
- σ represents the standard deviation.
Substituting the given parameters into the formula, we have;
Z-score, z = (128 - 70)/(20)
Z-score, z = 58/20
Z-score, z = 2.9
Read more on z-scores here: brainly.com/question/26714379
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(I think you mean x2 is x squared correct? if so) x^2+x^2-5x-x+7
2x^2-6x+7