Answer:
the answer should be 54.6 grams
The average score of all the students in both classes is 84.
<h3>How to calculate the average?</h3>
The class with 30 students had an average score of 80 on a test. The total score will be:
= 30 × 80
= 2400
A class with 20 students had an average score of 90 on the same test. The total score will be:
= 20 × 90
= 1800
Total scores = 2400 + 1800 = 4200
Number of students = 20 + 30 = 50
The average score will be:
= Total score / Total students
= 4200 / 50
= 84
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No because the sum could also be irrational number which for example it could be square root of 9 or 49
Hope this helps answer your question
Answer:
x = -0.17 and x = -5.83
Step-by-step explanation:
We are asked to solve the quadratic equation

We use the quadratic formula using a = 1, b = 6 and c = 1
for a general quadratic equation of the form: 
Then, the solutions are given by;

which produces the two following answers (rounded to two decimals):
x = -0.17 and x = -5.83
The usual margin of error we strive for is a 95% probability that our estimate is within the margin. Assuming a normal distribution (and that we have a big enough sample not to worry about t tests) that corresponds to between minus and plus two standard deviations of the mean (remember the 68-95-99.7 rule). So our margin of error is plus or minus two standard deviations.
Answer: ±2%