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
Assuming it is a Obtuse Scalene Triangle
Side a = 6
Side b = 15
Side c = 13.0767 = 3√19
Answer:
c .3.3
Step-by-step explanation:
pH is the negative log of the molar hydrogen ion concentration.The equation to calculate pH is;
pH = -log10[H+]
pH = -log10(5.0 x 10-4)
pH = 3.30
Answer: 2
Step-by-step explanation: five times 2 is 10 plus 10 would equal 20
