William went shopping for a new phone because of a sale. The store was offering a 15% discount. If the price on the tag was $41,
1 answer:
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Answer:
Step-by-step explanation:
Solve for the first variable in one of the equations, then substitute the result into the other equation.
Add the equations in order to solve for the first variable. Plug this value into the other equations in order to solve for the remaining variables.
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Answer:
a. About 96% of Spieth's drives travel at least 290 yards
b. The ball has to travel about 314.24 yards
Step-by-step explanation:
* Let us explain how to solve the problem
- The distance the ball travels can be modeled by distribution with
mean 304 yards and standard deviation 8 yards
a.
- Jordan would need to hit the ball at least 290 yards to have a clear
second shot that avoids a large group of trees
- We need to find the percent of Spieth's drives travel at least
290 yards
∵ The mean μ = 304 yards
∵ The standard deviation σ = 8 yards
∵ The distance x = 290
∵ P(x ≥ 290) = P(z ≥ z)
- We need to find z score
∵ z-score = (x - μ)/σ
∴ z = = -1.75
* Let us use the normal distribution table to find the corresponding
area of z = -1.75
∵ P(-z) = 1 - P(z)
∵ P(z ≥ -1.75) = 1 - 0.04006 = 0.95994
∴ P(x ≥ 290) = 0.96 = 96%
* <em>About 96% of Spieth's drives travel at least 290 yards</em>
b.
- On another golf hole, Spieth has the opportunity to drive the ball
onto the green if he hits the ball a distance in the top 10% of all
his drives
- We need to find how far the ball has to travel
- Let us find the z-score from the normal distribution table for the 10%
to the right or 90% to the left
∵ The area which equivalent to 0.9 ≅ 0.89973
∴ z = 1.28
∵ z-score = (x - μ)/σ
∴ 1.28 =
- Multiply both sides by 8
∴ 10.24 = x - 304
- Add 304 for both sides
∴ x = 314.24 yards
* <em>The ball has to travel about 314.24 yards</em>
Answer:
The prevalence of serious defects in this population at the time of birth is 10%.
Step-by-step explanation:
The prevalence of serious defects is the number of infants that were born with seriours birth defects divided by the total number of infants born.
In this problem, we have that:
There were 1000 newborn infants.
100 infants were born with serious birth defects.
Calculate the prevalence of serious defects in this population at the time of birth.
This is:
The prevalence of serious defects in this population at the time of birth is 10%.