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
First you have to make both fractions have the same denominator, so you can multiply each fraction by the others denominator.
5/8
To
(5*6)/(8*6)
And
1/6
To
(1*8)/(6*8)
Now it's 6 30/48 - 2 8/48
= 4 22/48
Now reduce to
= 4 11/24
So, 4 11/24 is the answer
Answer:
13
Step-by-step explanation:
b= 3
3x3= 9
9+4= 13
3x3+4=13
Hope this helps
Answer : 81 because it is the only one that is not a multiple of 4
Step-by-step explanation:
This is
{HH, TT, TH, HT} where H = head and T = tail
