Answer:
Step-by-step explanation:
Any expression that says (2 * 4)/3 is correct, even though there is a shift in the brackets. That means that A, B, C are all the same thing, and all are correct.
Only D is lying.
2*(1/3) = 2/3
4*(1/3) = 4/3 Now we have to add them
2/3 + 4/3 = 6/3 = 2
To show what the real answer is, try A
2*4/3
8/3 is the actual answer.
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:
11.C
12.B
Step by step explanation:
Answer:
D
Step-by-step explanation:
-3 and 3 are opposites but 5 (y), is the same
