4 and 5
This is because when you multiply 6 by 4 you get 24. Then you divide it by 5 which is 4.8, the answer lies between 4 & 5.
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:
80 minutes
Step-by-step explanation:
Rate and Time are inverses of each other
First,
Elise Time = 12
and
Katherine Time = 2 * 12 = 24
Their rates would be (inverses):
Elise Rate = 1/12
Katherine Rate = 1/24
Together their rate is 1/12 + 1/24 = 3/24
Now, the inverse of this rate would be the time it takes to complete 1 bag together, that is:
(3/24) ^ -1 = 24/3 = 8 minutes
So, 10 bags would take them:
8 * 10 = 80 minutes
Answer:
Answer C
Step-by-step explanation:
