Answer:
What are the possible answers?
Complete question :
The 100m dah times in the girl's track meet were normally distributed with a mean of 13 seconds and a standard deviation of 0.3 seconds.
Lana finished the race in 13.2 seconds . If 84 other girls ran in the event, approximately how many runners did she beat?
Answer:
21 runners
Step-by-step explanation:
Mean, μ = 13 seconds
Standard deviation, σ = 0.3
Lana's race time = 13.2
We find the proportion of runners who had race time above 13.2 ;
Proportion of who had race tune above 13.2
P(x > 13.2)
Obtain the Zscore
Zscore = (x - μ) / σ
Z = (13.2 - 13) / 0.3
Zscore = 0.2 / 0.3 = 0.6667
P(Z > 0.6667) = 0.25239 (Z probability calculator)
This is about 0.25239 * 100 = 25.24% = 25% (nearest percent)
Hence, Number of runners Lana beat = 25% of total runners ;
0.25 * 84 = 21
Hence, Lana beat about 21 runners
Answer:
the third one
Step-by-step explanation:
bc like there are 2 boxes of 1 and 5 boxes of 1/6 so thats already 2 and 5/6 which applies to all of them. then there is 1 box of 1 and 2 boxes of 1/3 so thats 1 and 1/3 which applies to all of them also but when you make them have the same denominator you get 2 and 5/6 + 1 and 4/6 which deletes the second one. When you add you should get the same denominator so that deletes the first one so then you simplify that and the fraction should still be equal to the unsimplified fraction so you should get 4 and 1/2 if that makes sense
