Answer: -3/7
Step-by-step explanation:
-3x + 5x +-3= 4x + 5x
7x=-3
x=-3/7
Answer:
200
Step-by-step explanation:
200-40% = 180
if we were to have 100-40% it would be 60 but since it's 200 it is now less of a % reduced
Answer:
first side=40
second side=20
third side=22
Step-by-step explanation:
LET THE SIDES OF THE TRIANGLES BE y
Perimeter=82
first side=2 x y = 2y
second side=y
third side=2 +y
2y + y + 2 + y=82
4y+2=82
4y= 82-2
4y=80
y=80/4
y=20
first side=2y=2(20)=40
second side=y=20
third side= 2 + y= 2 + 20 = 22
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: the answer is A
Step-by-step explanation: because the original question does not state that the swimmer “randomly selected” the members. It only says the swimmer “selects” 10 members. Therefore, it is A (The sample is not random)
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