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:
0.292371705 if A=17
0.258819045 if A=15
Step-by-step explanation:
What are all the other options i dont understand
Yes hope this helps man!!
Answer:
498
Step-by-step explanation:
For the blue block: 4(7x2) + 2(2x2) = 56 + 8 = 64
For green block: 4(12x7) + 2(7x7) = 336 +98 = 434
434 + 64 = 498
Answer:
"a" must be negative
Step-by-step explanation:
The slope between points (-1, 1) and (1, -1) is a minimum of (-1-1)/(1-(-1)) = -1.
The slope between points (1, -1 and (3, -4) is a maximum of (-4-(-1))/(3-1) = -3/2.
Thus, as x increases, the slope is decreasing. In order for that to be the case, the value of <em>a</em> must satisfy a < 0.
