1 1/6 hrs.....1 hr = 60 minutes......1/6 hr = 1/6(60) = 60/6 = 10 minutes....therefore, 1 1/6 hrs = 70 minutes
(7/8) / 70 = x / 1....7/8 of the wall to 70 minutes = x wall in 1 minute
cross multiply
(70)(x) = (7/8)(1)
70x = 7/8
x = (7/8) / 70
x = 7/8 * 1/70
x = 7 / 560 reduces to 1/80 <== she paints 1/80 of the wall in 1 minute
Using the Empirical Rule, it is found that the interval in which approximately 978 students scored was:
A. 72 < x < 88.5.
<h3>What does the Empirical Rule state?</h3>
It states that, for a normally distributed random variable:
- Approximately 68% of the measures are within 1 standard deviation of the mean.
- Approximately 95% of the measures are within 2 standard deviations of the mean.
- Approximately 99.7% of the measures are within 3 standard deviations of the mean.
The percentage that 978 is of 1200 is:
978/1200 x 100% = 81.5%.
Considering the symmetry of the normal distribution, two outcomes are possible involving 81.5% of the measures:
- Between one standard deviation below the mean and two above, which in the context of this problem is between 77.5 and 94.
- Between two standard deviations below the mean and one above, which in the context of this problem is between 72 and 88.5, which is option A in this problem.
More can be learned about the Empirical Rule at brainly.com/question/24537145
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Answer:
Step-by-step explanation:
38.
37.
42.5 cm. Do you want me to explain it?
The answer would be 168 minutes.
