If jenn has 13 fewer marbles than marty and we know she has 20 marbles, you would add 13 to 20 (33) to find how many marbles marty has. the equation would be 13+20=33 (or any variable depending on the context of the question.)
The first standard deviation covers about 68% of the distribution in a normal curve. (34% higher, 34% lower than the mean). the second standard deviation covers 28% (14% between 1st and 2nd SD above the mean, 14% between 1st and 2nd SD below the mean). In our case
1 Standard deviation = 27 hours (we will approximate to 25 hours)
Mean = 2,000
This means that 34% of the distribution is between 1975 and 2000 hours (within 1 standard deviation below the mean)
2,000- 2,050 covers the range within 50 hours above the mean.
50 hours is roughly 2 standard deviations. The second standard deviation (standard deviation between 1 and 2) covers around 14% on each side of the distribution.
50 hours is roughly 2 standard deviations, which means we add 34% + 14% = 48%.
The range of 1,975 - 2,050 hours covers 34% of the distribution below the mean and 48% of the distribution above the mean.
This means that the probability that the light bulb will last somewhere within this range is 34% + 48% = 82%
The closest answer is 79%. The difference can be explained by the fact that, for simplicity, we approximated the standard deviation to be ~25 hours instead of the real standard deviation of 27 hours.
Answer:
it's 6n + 7
Step-by-step explanation:
hope this helped a little bit :))
