URGENT BRAINLIEST GIVEN Mr Brown gives his class a test.
The 10 girls in the class get a mean mark of 70%.
The 15 boys in the class get a mean mark of 80%.
Nick says that because the mean of 70 and 80 is 75 then the mean mark for the whole class in the test is 75%. Nick is not correct.
Is the correct mean less than or greater than 75%?
You must justify your answer.
Answers
This is the way I do it to find the average.
10 girls times 70 = 700
15 boys times 80= 1200
700+1200=1900 all their scores
1900÷25 (number of boys and girls)=76 or 76%
Final answer:
Nick's statement is incorrect because he has averaged the mean scores, not the total scores. The correct mean score for the combined class is 76%, which is greater than 75%.
Explanation:
The subject of this question is Mathematics, particularly focused on the concept of averages or mean. This question is asking about the combined average (mean) percentage score for a class test. Nick's statement is incorrect because he has simply taken the mean of the girls' mean score and the boys' mean score.
Here's the correct way to find the mean: Multiply the mean score of the girls by the number of girls, then do the same for the boys. Then sum those numbers up and divide by the total number of students. Let's calculate:
- The total percentage for the girls is 70% * 10 = 700%.
- The total percentage for the boys is 80% * 15 = 1200%.
- Then combine these scores: 700% + 1200% = 1900%.
- Next, divide this by the total number of students (10 girls + 15 boys = 25 students): 1900% / 25 = 76%.
Therefore, the mean score for the whole class is 76%, which is greater than 75%.
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Answers
Answer:
(a) 3x -y = 7
(b) x +3y = 29
Step-by-step explanation:
(a) The standard form of the given line is ...
3x -y = 5
The parallel line will have a constant on the right that makes it go through (5, 8), so it will be ...
3x -y = 3(5) -(8)
3x -y = 7
__
(b) The perpendicular line will have coefficients for x and y swapped and one of them negated. Again, the constant is chosen to make it go through (5, 8).
x + 3y = (5) +3(8)
x + 3y = 29
B.7
C.10
D.13
Answers
Gordy played in:
65% of 20 games = 65% * 20 = 65/100 * 20 = 13 games
He did not play in:
20 games - 13 games = 7 games
The correct result would be B. 7 games.
B.7 is the answer.
Answers
Therefore your answer is 26.5%.
The correct answer is:
26.5%.
Explanation:
"Percent" means "per hundred", or "out of 100."
Our fraction is out of 200. To change this to something out of 100, we would divide the numerator and denominator by 2:
A.carbohydrate
B.Protein
C.DNA
D.lipid
Answers
Answer:
C
Step-by-step explanation:
a gene is what is in you so it starts with DNA
Answers
To represent the relationship between the set number and the number of sit-ups, you can use a simple verbal description: "The number of sit-ups in each set is half of the number in the previous set". The relationship between the set number and the number of sit-ups can be represented as a geometric sequence, where each set has half the number of sit-ups as the previous set. This can be calculated using the formula for a geometric sequence.
To represent the relationship between the set number and the number of sit-ups that Calvin and Mike do, you can use a mathematical expression or formula. In this case, the number of sit-ups in each set decreases by half compared to the previous set. You can express this relationship using an exponential decay formula:
Where:
represents the number of sit-ups in the nth set.
is the initial number of sit-ups in the first set (which is 64 in this case).
represents the reduction factor, as each subsequent set has half as many sit-ups.
n is the set number.
Using this formula, you can easily calculate the number of sit-ups in any set. For example, to find the number of sit-ups in the 4th set (n = 4), you would substitute n = 4 into the formula:
So, in the 4th set, Calvin and Mike do 8 sit-ups. This formula allows you to determine the number of sit-ups for any set without manually calculating each time.
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Answer:
64/2=32 32/2=16 16/2=8 8/2=4 4/2=2 2/2=1
Step-by-step explanation:
if you were to use a in and out chart you can you can set the in as the starting amount (64) and make the out/formula ÷2
Answers
length(L) = 5/9 miles
width (W)= ?
area = L * W
25/54 = 5/9 * W
W = (25/54) / (5/9) = (25 * 9) / (54 * 5)
W = 5/6 miles