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
Step-by-step explanation:
4(px + 1) = 64
Step 1: Add -4 to both sides.
4px + 4 -4 = 64 + -4
4px = 60
Step 2: Divide both sides by 4p.
<u>4px</u> = <u>60</u>
4p 4p
x = <u>15</u>
p
Answer:
A. 57.6
Step-by-step explanation:
6 times 5.2 is 31.2. 4 times 5 is 20. 6 times 5 is 30. 6 times 5 is 30. (31.2/2)+(20/2)+30= 55.6 Then you round nearest tenth. 57.6.
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Answer:
a.
Step-by-step explanation:
For an even-index radical, ...
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This lets us simplify the given expression as follows:
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