Answer:
x=5 and y=8
Step-by-step explanation:
Find x:
3x - 2 = x + 8
-x -x
2x - 2 = 8
+2 +2
2x = 10
---- ----
2 2
x = 5
Find y:
6y - 7 = y + 33
-y -y
5y - 7 = 33
+7 +7
5y = 40
---- -----
5 5
y = 8
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:
x = 7
Step-by-step explanation:
=> 9/72 = 3x-20/56
=> 9×45/72 = 3x-20
=> 27/3 = x
=> x = 7
Answer:
114,400 and 118,976.
Step-by-step explanation:
Let's represent this using a function. Let's let:
represent the total population, and 
represent the total number of years since last year.
We know that the population grows by 4% every year or 0.04 every year. This is exponential growth. We can write this as:
Note that the coefficient is 110000 because that is the year we are starting with. Also, note that it is 1.04 because we are essentially adding .04 to the original population.
Anyways, to find the present population, set y equal to 1 (because 1 year after last year is the present year)
The present population is 114,400 people.
For next year, set y equal to 2 (2 years after last year is next year)>
The population next year will be 118,976 people.
Answer:397.1....i think
Step-by-step explanation:
