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:
k = 23
Step-by-step explanation:
Answer:
Step-by-step explanation:
complimentary angles, when added = 90 degrees
69 + 5n + 1 = 90
5n + 70 = 90
5n = 90 - 70
5n = 20
n = 20/5
n = 4 <====
Megabyte difference = 96 - 24 = 72
time difference = 1:15 - 1:10 = 15 min.
Download rate would be: 72 / 15 = 4.8
So, Your Answer would be 4.8 mb/min
Hope this helps!
Simplifying
j = (2j + 3)
Reorder the terms:
j = (3 + 2j)
Remove parenthesis around (3 + 2j)
j = 3 + 2j
Solving
j = 3 + 2j
Solving for variable 'j'.
Move all terms containing j to the left, all other terms to the right.
Add '-2j' to each side of the equation.
j + -2j = 3 + 2j + -2j
Combine like terms: j + -2j = -1j
-1j = 3 + 2j + -2j
Combine like terms: 2j + -2j = 0
-1j = 3 + 0
-1j = 3
Divide each side by '-1'.
j = -3
Simplifying
j = -3
