Answer:
Unknown answer so ye that mean I'm not sure about it
Step-by-step explanation:
Unknown answer so ye that mean I'm not sure about it
Answer: 0.0228
Step-by-step explanation:
Given : The mean and the standard deviation of finish times (in minutes) for this event are respectively as :-

If the distribution of finish times is approximately bell-shaped and symmetric, then it must be normally distributed.
Let X be the random variable that represents the finish times for this event.
z score : 

Now, the probability of runners who finish in under 19 minutes by using standard normal distribution table :-

Hence, the approximate proportion of runners who finish in under 19 minutes = 0.0228
The missing coefficient of the x-term after finding the product of (-x - 5)², is: C. 10.
<h3>What is the Coefficient of a Variable?</h3>
The coefficient of a variable is the numerical value that comes before the variable and multiplies it.
Find the product of (-x - 5)²:
(-x - 5)(-x - 5)
-x(-x - 5) -5(-x - 5)
x² + 5x + 5x + 25
x² + 10x + 25
The x-term is "10x". The coefficient is: 10.
Learn more about the coefficient of a variable on:
brainly.com/question/16895867
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Given:
The ratio of red and blue cubes is 4:7.
After adding 10 more red cubes the ratio of red and blue cubes is 6:7.
To find:
The number of blue cubes.
Solution:
The ratio of red and blue cubes is 4:7.
Let the number of red and blue cubes be 4x and 7x respectively.
After adding 10 more red cubes.
Number of red cubes = 4x+10
Then, the ratio of red and blue cubes is 6:7.





Divide both sides by 14.

Now,
Number of blue cubes in the bag is

Therefore, the number of blue cubes is 35.