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
Archy [21]
2 years ago
13

The cross section of a parabolic sound reflector at the Olympics has a diameter of 20 inches and is 25 inches deep. Write an equ

ation that represents the cross section of the reflector with its vertex at ( ) 0, 0 and its focus to the left of the vertex.
Mathematics
1 answer:
Arturiano [62]2 years ago
7 0

Answer: 69

Step-by-step explanation: Sorry I do not know the answer because I am not smart.  I just need the points so I can answer more questions.  Have a great day though and I wish you luck with your question:)

You might be interested in
Somebody explain pls!!!!!
Furkat [3]

Step-by-step explanation:

Using log properties

log_{7}(rz {}^{12} )

log_{7}(r)  +  log_{7}(z {}^{12} )

Then

log_{7}(r)  + 12 log_{7}(z)

Plug in the knowns

- 7.87 + 12( - 12.59)

- 158.95

5 0
11 months ago
Please answer all parts of the question and all work shown.
faust18 [17]

Answer:

a. 0.4931

b. 0.2695

Step-by-step explanation:

Given

Let BG represents Boston Globe

NYT represents New York Times

P(BG) = 0.55

P(BG') = 1 - 0.55 = 0.45

P(NYT) = 0.6

P(NYT') = 1 -0.6 = 0.4

Number of headlines = 5

Number of depressed articles = 3 (at most)

a.

Let P(Read) = Probability that he reads the news the first day

P(Read) = P(He reads BG) and P(He reads NYT)

For the professor to read BG, then there must be at most 3 depressing news

i.e P(0) + P(1) + P(2) + P(3)

But P(0) + P(1) + .... + P(5) = 1 (this is the sample space)

So,

P(0) + P(1) + P(2) + P(3) = 1 - P(4) - P(5)

P(4) or P(BG = 4) is given as the binomial below

(BG + BG')^n where n = 5, r = 4

So, P(BG = 4) = C(5,4) * 0.55⁴ * 0.45¹

P(BG = 5). = (BG + BG')^n where n = 5, r = 5

So, P(BG = 5) = C(5,5) * 0.55^5 * 0.45°

P(0) + P(1) + P(2) + P(3)= 1 - P(BG = 4) - P(BG = 5)

P(0) + P(1) + P(2) + P(3) = 1 - C(5,4) * 0.55⁴ * 0.45¹ - C(5,5) * 0.55^5 * 0.45°

P(0) + P(1) + P(2) + P(3) = 0.7438

For the professor to read NYT, then there must be at most 3 depressing news

i.e P(0) + P(1) + P(2) + P(3)

But P(0) + P(1) + .... + P(5) = 1 (this is the sample space)

So,

P(0) + P(1) + P(2) + P(3) = 1 - P(4) - P(5)

P(4) or P(NYT = 4) is given as the binomial below

(NYT+ NYT')^n where n = 5, r = 4

So, P(NYT = 4) = C(5,4) * 0.6⁴ * 0.4¹

P(NYT = 5). = (NYT + NYT')^n where n = 5, r = 5

So, P(NYT = 5) = C(5,5) * 0.6^5 * 0.4°

P(0) + P(1) + P(2) + P(3)= 1 - P(NYT = 4) - P(NYT = 5)

P(0) + P(1) + P(2) + P(3) = 1 - C(5,4) * 0.6⁴ * 0.4¹ - C(5,5) * 0.6^5 * 0.4°

P(0) + P(1) + P(2) + P(3) = 0.6630

P(Read) = P(He reads BG) and P(He reads NYT)

P(Read) = 0.7438 * 0.6630

P(Read) = 0.4931

b.

Given

n = Number of week = 7

P(Read) = 0.4931

R(Read') = 1 - 0.4931 =

He needs to read at least half the time means he reads for 4 days a week

So,

P(Well-informed) = (Read + Read')^n where n = 7, r = 4

P(Well-informed) = C(7,4) * (0.4931)⁴ * (1-0.4931)³ = 0.2695

3 0
3 years ago
2. Kelsea needs a test average of at least 90 to get an "A-" this marking period in math. Her three test grades
Luda [366]

Answer:

<u>Equation:  87 + 91 + 86 + x = 360</u>

<u>Solution: 264 + x = 360</u>

<u>x = 360 - 264</u>

<u>x = 96</u>

Step-by-step explanation:

1. Let's review the information given to us to answer the question correctly:

First three Kelsea's test grades : 87, 91 and 86

2. What score must she get on her fourth test to receive at least an A- ?

Define variable:  x that represents the grade needed by Kelsea on her fourth test to receive at least an A-

Equation:  87 + 91 + 86 + x = 360

Solution: 264 + x = 360

x = 360 - 264

x = 96

<u>Now you can understand if the previous work you did is correct</u>

6 0
3 years ago
a computer diagnostic program has completed 2/3 of it's analysis. if the analysis requires 1 second to complete 1/6 of the analy
Svet_ta [14]
The computer will finish in 2 seconds

2/3 = 4/6
1 = 6/6
6/6 - 4/6 = 2/6
4 0
3 years ago
Read 2 more answers
The scatterplot below shows the average yearly consumption of bottled water by people in the United States starting in 1990. Usi
lina2011 [118]
Where is the question chart/graph?
8 0
3 years ago
Other questions:
  • the assembly machine in your plant can produce 36,200 parts in 9 hours. How many parts can it produce in 18 hours
    9·1 answer
  • Find the area of the semicircle .
    5·1 answer
  • The volume of the above solid is?
    11·1 answer
  • The product of eight and the sum of a number and nine
    7·1 answer
  • PLEASE HELP I NEED IT QUIK<br><br> I need help with b and c putting it on the graph PLEASE HELP
    9·1 answer
  • Please help me I will give you the briain thing and extra points. (image below) 9/13
    12·2 answers
  • What equation would help determine the cost of 4 markers if five markers are $6.55 and remember I am asking for the equation not
    7·1 answer
  • 43 grams of copper and 7grams other metals in a birdhouse, 83 grams of copper and 17 grams of other metals. Which one has more c
    7·1 answer
  • PLEASE HELP ME THIS I DUE MONDAY
    13·2 answers
  • Which of the following ratios are equivalent to 20% ? 5:15 , 1:5 , 2:5 , 3:12 , 4:20
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!