The answer is a or b it’s one of them
Answer:
The variance for the number of correct answers is 2.8 questions
Step-by-step explanation:
The number of correct answers follows binomial distribution, in which we have:
- n identical and independents events: the 15 questions
- two possibles results that we call success and fail: The answer is correct and the answer is incorrect
- probability p of success and 1-p of fail. Probability 1/4 of get the answer correct and probability of 3/4 of get the answer incorrect. This probabilities are calculated on that way because every question have 4 possible answers and one of which is correct.
So, the variance for a variable x that follows a Binomial distributions is:
V(x)=n*p*(1-p)
Then, the variance for the number of correct answers is:
V(x)=15*(1/4)*(3/4) = 2.8125 ≈ 2.8
Because n is equal to 15, p is equal to 1/4 and (1-p) is equal to 3/4.
Answer:
a = 9.4 cm
b = 12.0 cm
Step-by-step explanation:
Check the image uploaded for diagram;
For the first diagram, side length a is calculated as follows;
a² = 8² + 5²
a² = 64 + 25
a² = 89
a = √89
a = 9.4 cm ( approximated to 1 decimal place)
For the second diagram, side length b is calculated as follows;
b² = 17² - 12²
b² = 145
b = √145
b = 12.0 cm (approximated to 1 decimal place)
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Change each of the options into percentage
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Option A: Decimal to percentage: x100
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0.14 x 100 = 14%
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Option 2: Fraction to percentage: x100
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5/7 x 100 = 71.4%
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Option C: Fraction to percentage: x 100
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12/5 x 100 = 240%
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Option D: Decimal to percentage: x 100
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1.4 x 100 = 140%
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Answer D
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Hello!
If there is 4 faces and 1/4 chance of any side end up face down, we just have to decrease one chance, so, the chance of the face "2" does not end up face down is equal the sum of the chances of the others faces end up face down, so, we have: 3/4.
Hugs!
