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:
51m
Step-by-step explanation:
-Paul is 6ft, and has a 10ft shadow. The pole has a 85ft shadow:
-Using ratios:
Let h be the height of the flagpole:
Hence, the height of the pole is 51m
Slope = rise/run =[y2-y1]/[x2-x1]
1) slope = [90 - 30] / [12 - 4] = 60 / 8 = 15/2
2) slope = [75 - 30] / [10 - 4] = 45 / 6 = 15 / 2
The slopps are equal.
The measure of angle J is 19.8°, and the correct option is D.
<h3>What is the formula of cosine?</h3>
The law of cosine or cosine rule in trigonometry is a relation between the side and the angles of a triangle. Suppose a triangle with sides a, b, c and with angles cosC.
The following formula is used to find the angle j is;
Triangle HIJ has side lengths h=12, i = 17, j = 7.
Substitute all the values in the formula;
Hence, the measure of angle J is 19.8°, and the correct option is D.
Learn more about law cosine here;
brainly.com/question/17289163
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