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 answer is(5)
Step-by-step explanation:
Answer:
Step-by-step explanation:
B
125.63 (dollars) / 18.25 (hrs) = 6.88384 dollars per hr....he just figure out what he made per hr...and when rounded, he made about 6.88 per hr
The answer choice that correctly calculates and interprets the standard deviation of the sum, S = X + Y is D. Sigma Subscript s = 0.8; companies A and B can expect the total weight of packages to vary by approximately 0.8 ounces from the mean.
<h3>What does the standard deviation means?</h3>
A standard deviation means the all measure of how dispersed the data is in relation to the mean. It should be noted that low standard deviation means that the data are clustered around the mean, and the high standard deviation means that the data are more spread out.
In this case, the answer choice that correctly calculates and interprets the standard deviation of the sum, S = X + Y is the sigma Subscript s = 0.8; companies A and B can expect the total weight of packages to vary by approximately 0.8 ounces from the mean.
In conclusion, the correct option is D.
Learn more about standard deviation on:
brainly.com/question/12402189
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