1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
bezimeni [28]
3 years ago
15

A set of magical wand prices are normally distributed with a mean of 50 dollars and a standard deviation of 4 dollars. A blackth

orn wand has a price of 45.20
Mathematics
1 answer:
Anna11 [10]3 years ago
8 0

Complete Question

A set of magical wand prices are normally distributed with a mean of 50 dollars and a standard deviation of 4 dollars. A blackthorn wand has a price of 45.20. What proportion of wand prices are lower than the price of the blackthorn wand? You may round your answer to four decimal places

Answer:

0.1151

Step-by-step explanation:

We solve using z score formula

z = (x-μ)/σ, where

x is the raw score = $45.20

μ is the population mean = $50

σ is the population standard deviation = $4

We are solving for x < 45.20

Hence:

z = 45.20 - 50/4

z = -1.2

Probability value from Z-Table:

P(x<45.20) = 0.11507

Approximately to 4 decimal places = 0.1151

Therefore, the proportion of wand prices that are lower than the price of the blackthorn wand is 0.1151

You might be interested in
Like what's the snyomon of car
weqwewe [10]
Vehicle can be a synonym for car
4 0
3 years ago
Read 2 more answers
Someone help please I'm really stuck on these questions and I need help please I need to bring this in tomorrow please help
AysviL [449]
1) 1
2) PA: between 2 and 3.
2) PB: Unsure about it.
7 0
3 years ago
In October of 2012, Apple introduced a much smaller variant of the Apple iPad, known at the iPad Mini. Weighing less than 11 oun
sveticcg [70]

Answer:

a. f_X(x) = \dfrac{1}{3.5}8.5

b. the probability that the battery life for an iPad Mini will be 10 hours or less is 0.4286 which is about 42.86%

c.  the probability that the battery life for an iPad Mini will be at least 11 hours is 0.2857 which is about 28.57 %

d. the probability that the battery life for an iPad Mini will be between 9.5 and 11.5 hours is 0.5714 which is about 57.14%

e.  86 should have a battery life of at least 9 hours

Step-by-step explanation:

From the given information;

Let  X represent the continuous random variable with uniform distribution U (A, B) . Therefore the probability  density function can now be determined as :

f_X(x) = \dfrac{1}{B-A}A

where A and B  are the two parameters of the uniform distribution

From the question;

Assume that battery life of the iPad Mini is uniformly distributed between 8.5 and 12 hours

So; Let A = 8,5 and B = 12

Therefore; the mathematical expression for the probability density function of battery life is :

f_X(x) = \dfrac{1}{12-8.5}8.5

f_X(x) = \dfrac{1}{3.5}8.5

b. What is the probability that the battery life for an iPad Mini will be 10 hours or less (to 4 decimals)?

The  probability that the battery life for an iPad Mini will be 10 hours or less can be calculated as:

F(x) = P(X ≤x)

F(x) = \dfrac{x-A}{B-A}

F(10) = \dfrac{10-8.5}{12-8.5}

F(10) = 0.4286

the probability that the battery life for an iPad Mini will be 10 hours or less is 0.4286 which is about 42.86%

c. What is the probability that the battery life for an iPad Mini will be at least 11 hours (to 4 decimals)?

The battery life for an iPad Mini will be at least 11 hours is calculated as follows:

P(X\geq11) = \int\limits^{12}_{11} {\dfrac{1}{3.5}} \, dx

P(X\geq11) =  {\dfrac{1}{3.5}} (x)^{12}_{11}

P(X\geq11) =  {\dfrac{1}{3.5}} (12-11)

P(X\geq11) =  {\dfrac{1}{3.5}} (1)

P(X\geq11) = 0.2857

the probability that the battery life for an iPad Mini will be at least 11 hours is 0.2857 which is about 28.57 %

d. What is the probability that the battery life for an iPad Mini will be between 9.5 and 11.5 hours (to 4 decimals)?

P(9.5 \leq X\leq11.5) =\int\limits^{11.5}_{9.5} {\dfrac{1}{3.5}} \, dx

P(9.5 \leq X\leq11.5) ={\dfrac{1}{3.5}} \, (x)^{11.5}_{9.5}

P(9.5 \leq X\leq11.5) ={\dfrac{1}{3.5}} (11.5-9.5)

P(9.5 \leq X\leq11.5) ={\dfrac{1}{3.5}} (2)

P(9.5 \leq X\leq11.5) =0.2857* (2)

P(9.5 \leq X\leq11.5) =0.5714

Hence; the probability that the battery life for an iPad Mini will be between 9.5 and 11.5 hours is 0.5714 which is about 57.14%

e. In a shipment of 100 iPad Minis, how many should have a battery life of at least 9 hours (to nearest whole value)?

The probability that battery life of at least 9 hours is calculated as:

P(X \geq 9) = \int\limits^{12}_{9} {\dfrac{1}{3.5}} \, dx

P(X \geq 9) =  {\dfrac{1}{3.5}}(x)^{12}_{9}

P(X \geq 9) =  {\dfrac{1}{3.5}}(12-9)

P(X \geq 9) =  {\dfrac{1}{3.5}}(3)

P(X \geq 9) =  0.2857*}(3)

P(X \geq 9) =  0.8571

NOW; The Number of iPad  that should have a battery life of at least 9 hours is calculated as:

n = 100(0.8571)

n = 85.71

n ≅ 86

Thus , 86 should have a battery life of at least 9 hours

3 0
3 years ago
A pilot approaching a 3000-meter runway finds that the angles of depression of the ends of the runway are 14° and 20°. How far i
Amanda [17]
Answer:  The plane is 6,547 feet from the closer edge of the runway.

This is a trigonometry problem that will involve setting up 2 different triangles. One going to the closer edge of the runway and the other going to the far end of the runway.

The constant between the 2 triangles is the height of the plane. You can solve for this is both triangles and set them equal to each other. 

Do that will give you the equation:

x/tan(70) = (x+3000)/tan(76) where x is the distance to the closer end of the runway. 

If you solve that equation, you will get x = 6547 feet.

7 0
3 years ago
Practice Exercise 1:
Rudiy27

Answer:

Step-by-step explanation:

A

4 0
3 years ago
Other questions:
  • <img src="https://tex.z-dn.net/?f=x%20%7B2%7D%20%3D%20%20%5Cfrac%7B25%7D%7B144%7D%20" id="TexFormula1" title="x {2} = \frac{25}
    14·1 answer
  • I need help with this one
    10·2 answers
  • Para calcular 1/7 de 2/5
    13·1 answer
  • 80/91 + 5/9 in fraction pls
    5·2 answers
  • X + y = -2<br> -x + y = 6<br> Solve the linear system
    7·1 answer
  • HELP ASAP
    13·2 answers
  • Could you please show the work for both of them?​
    10·1 answer
  • I like this game some people dont
    9·2 answers
  • A restaurant sells 10 tacos for $8.49, or 6 of the same kind of taco for $5.40. Which is a better deal? Explain how you know.
    14·1 answer
  • Divide. give the quotient and remainder.<br> 4036/5
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!