Answer:
b = 12
Step-by-step explanation:
b/3 + 4 = 8
subtract 4 on both sides
b/3 = 4
multiply 3 with 4
b = 12
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
Length is 48 ft
The perimeter of a rectangle is equal to the sum of all side’s.
2(lengths)+2(widths)= perimeter
Length=3x+4
Now given the perimeter of 140
3(3x+4)+3(x)=140
9x+12+3x=140
12x+12=140
12x=128
X= 10.7
10.7 is the width
Length=3x+4
Length =3(10.6)+4
Length=31.8+4
Length=35.8
Answer = 35.8
This can only be answered if you were given a perimeter.
Answer:
he can run 5 meters in 1 min
Step-by-step explanation:
S = d/t
S=100m/20s
S=5m/s
