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
Here:
PFA for the answers. The numbering might confuse you. It goes from the 1 to the last marked question in ascending order. Hope it helps you. ~BYE
The steps of the solution into order to solve for x in the equation 6(x-5) = 54 are:
- A. 6x – 30 = 54
- B. 6x = 84
- D. x = 14
Given the expression 6(x-5) = 54
Expand the expression in parenthesis using the distributive law;
6x - 6(5) = 54
6x - 30 = 54
Add 30 to both sides
6x - 30 + 30 = 54 + 30
6x = 84
Divide both sides by 6
6x/6 = 84/6
x = 14
Therefore the steps of the solution into order to solve for x in the equation 6(x-5) = 54 are:
- A. 6x – 30 = 54
- B. 6x = 84
- D. x = 14
Learn more on equations here; brainly.com/question/2972832
9 hrs and 35 minutes he would have traveled. Hope I helped.