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
A.209
<span>276.37 – 67.81 = 208.56
The 5 in .56 means round up.
This means 208.56 will turn into 209.</span>
Answer:
okay depending on the question
Answer:
A
Step-by-step explanation:
X<Y means x is less than y-5 and you get A.
X = quarters
y = dimes
0.25x + 0.10y = 6.95 or 25x + 10y = 695
x + y = 44
25x + 10y = 695
25 (x + y = 44)
25x + 10y = 695
25x + 25y = 1,100
-15y = -405
y = 27 dimes
and 17 quarters