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
coldgirl [10]
3 years ago
14

Refer previous problem. Suppose that you wish to estimate the difference between the mean acidity for rainfalls at two different

locations. If you wish your estimate to be correct to the nearest 0.1 pH with probability near 0.90, approximately how many rainfalls (pH values) must you include in each sample?

Mathematics
1 answer:
aivan3 [116]3 years ago
7 0

Answer:

Hence,we need at least 136 rainfall PH values in the sample i.e

n ≥ 136

Step-by-step explanation:

We are given that:

(σ1)^2 = (σ2)^2 = Population variance = 0.25

So, E < 0.1

Confidence coefficient (c) = 0.9

n = n1 = n2

For confidence level, 1 - α = 0.9,we'll determine Z (α /2) = Z 0.05 by looking up 0.005 using the normal probability table which i have attached.

So, Z (α /2) = 1.645

The margin of error E is given as;

E = Z (α /2)√[(σ1)^2)/n1] + [(σ2)^2)/n2]

= Z (α /2)√({(σ1)^2 + (σ2)^2}/n) < 0.1

Multiply both sides by √n to get;

Z (α /2)√(σ1)^2 + (σ2)^2} < 0.1√n

Divide both sides by 0.1;

{Z (α /2)√(σ1)^2 + (σ2)^2}}/0.1 <√n

When we square each side, we get

{Z (α /2)√(σ1)^2 + (σ2)^2}}/0.1} ^2 < n

We'll now fill in the known values and solve;

n > ( 1.645 x √{(0.25 + 0.25)/0.1}^2

n > 135.3 or approximately n > 136

Hence,we need at least 136 observations in the sample i.e

n ≥ 136

You might be interested in
Pls help, I cannot do this and it is due 8-28-20
Jet001 [13]

Answer:

20. J, 21. B

Step-by-step explanation:

20. P = 15 (2) + 8 (2)

      P = 36 ft.

21. 15 - 6 = 9 ft.

8 0
3 years ago
Read 2 more answers
Need help with numbers 5-12
Liula [17]
5. Positive 
6. Negative 
7. Negative 
8. Positive 
9. No correlation 
10. Positive 
11. No correlation 
12. Positive 
6 0
3 years ago
Mr. Greenjeans planted 6 different crops on 2 acres of land. If half of it was planted with green beans, how many acres were pla
scoundrel [369]
If half of two acres was planted with green beans, the answer would be one acre
5 0
3 years ago
What is the volume of a cone-shaped popcorn cup that is 8 inches tall and 6 inches across at the base?
Alina [70]

The volume of cone shaped popcorn cup is 75.36 cubic inches.

According to the given question.

The height of the popcorn cup = 8inches

And the diameter of the cup = 6 inches

⇒ Radius of the popcorn cup = 6/2 = 3 inches

As we know that, the volume of cone is calculated by the formula

volume of cone = (πr^2h)/3

Therefore, the volume of cone shaped popcorn cup

= 3.14((3)^2)(8)/3

= 3.14(3)(8)

= 75.36 cubic inches

Hence, the volume of cone shaped popcorn cup is 75.36 cubic inches.

Find out more information about volume of cone here:

brainly.com/question/23173618

#SPJ4

8 0
1 year ago
The odds in favor of a horse winning a race are 7:4. Find the probability that the horse will win the race.
Sliva [168]

Answer:

7/11 = 0.6363...

Step-by-step explanation:

7 + 4 = 11

probability of winning: 7/11 = 0.6363...

7 0
3 years ago
Other questions:
  • the vega family has a cell phone plan that costs $75 per month including taxes and fees. the plan lets the 5 members of the vega
    8·1 answer
  • Solve the Application.
    5·2 answers
  • paulita reads an average of 20 pages each day. she has six days to read 100 pages . will she finish her reading in 6 days? Expla
    11·1 answer
  • Connor has a collection of dimes and quarters with a total value of $6.30. The number of dimes is 14 more than the number of qua
    13·1 answer
  • Show all work to identify the asymptotes and zero of the function f of x equals 5 x over quantity x squared minus 25.
    14·1 answer
  • I need helps with this
    8·1 answer
  • Julius has a garden that has dimensions of 12 ft by 20 ft. Julius needs more room to plant some peppers, and determines the gard
    5·1 answer
  • 30,14,25,,13,33,14 the missing value is?
    12·1 answer
  • Go Which operation would be completed second in the following expression? 7² -3+9+8 dividend by two
    10·2 answers
  • What is 34107.12cm to the nearest half centimeters?  please explain
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!