Answer:29.2
Step-by-step explanation:
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
1 hour = 70 miles
3 hours = 70 x 3
= 210 miles
The answer would be 210 miles.
Statements that are always true are:1. Several congruent angles are formed.4. Supplementary angles are formed.Other statements are not always true when a transversal crosses parallel lines.
Answer:
Step-by-step explanation:
11 - 19 - 4 - (-8) =
11 - 19 - 4 + 8 =
- 23 + 19 =
- 4 <===
