Aphysical fitness association is including the mile run in its secondary-school fitness test. the time for this event for boys in secondary school is known to possess a normal distribution with a mean of 450 seconds and a standard deviation of 50 seconds. find the probability that a randomly selected boy in secondary school will take longer than 335 seconds to run the mile.

a) 0.5107

b) 0.9893

c) 0.0107

d) 0.4893

The probability that a randomly selected boy in secondary school will

take longer than 335 seconds to run the mile is 0.9893 ⇒ answer B

Step-by-step explanation:

- A physical fitness association is including the mile run in its

  secondary-school fitness test

- The time for this event for boys in secondary school is known to

  possess a normal distribution with a mean of 450 seconds and a

  standard deviation of 50 seconds

∴ μ = 450 seconds

∴ σ = 50 seconds

- We need to find the probability that a randomly selected boy in

  secondary school will take longer than 335 seconds to run the mile

- We must to find z-score for x > 335 seconds

∵ z = (x - μ)/σ

∵ x = 335 seconds , μ = 450 seconds , σ = 50 seconds

- substitute the values in the rule above

∴ z = = -2.3

- Use the normal distribution table of z to find the corresponding area

  of z-score

∵ P(-2.3) = 0.01072

- We need to find the area to the right of the z-score

∴ P( x > 335) = 1 - 0.01072 = 0.9893

* The probability that a randomly selected boy in secondary school

  will take longer than 335 seconds to run the mile is 0.9893

y-y1=4(x-x1)

step-by-step explanation:

this is point-slope form since you only have 4 as the slope it goes in place of m

hope this : )

b: |12 – x| ≤ 0.25

step-by-step explanation:      

let x be the possible lengths in inches, of the ribbons jaime cut.

we have been given that jaime is cutting strips of ribbon for a project. he tries to cut each piece to be 12 inches long, but sometimes he cuts it too long or too short by as much as 0.25 inch.  

we can represent this information in an inequality as:

by the definition of absolute value function we will get,

upon combining our inequalities we will get,

therefore, the inequality   describes all the possible lengths (x), in inches, of the ribbons jaime cut.

step-by-step explanation: