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
loris [4]
3 years ago
11

A limnologist wishes to estimate the mean phosphate content per unit volume of lake water. It is knownfrom studies in previous y

ears that the standard deviation has a fairly stable value ofσ= 4. How manyindependent water samples must the limnologist analyze to be 90% certain that the error of estimation [halfwidth of 90% confidence interval] does not exceed 0.8 milligrams?
Mathematics
1 answer:
telo118 [61]3 years ago
6 0

Answer: 68

Step-by-step explanation:

As per given , we have

Population standard deviation : \sigma=4

Critical value for  90% confidence interval =z_{\alpha/2}=1.645

Margin of error : E= 0.8 milligrams

The formula to find the sample size is given by :-

n=(\dfrac{z_{\alpha/2}\ \sigma}{E})^2

i.e. n=(\dfrac{(1.645)(4)}{0.8})^2=(8.225)^2

=67.650625\approx68

Hence, the limnologist must analyze 68 samples.

You might be interested in
The lot is 48 feet wide.<br> The dividers are each 2 feet wide.
ivann1987 [24]
The answer is 24 bc 48 divided by 2 equals 24
7 0
2 years ago
Please help!!!! Whoever answers these three questions correctly first will get brainliest answer!!!!!
inna [77]
4. -8
5. 24
6. I can't see it properly so if it's ÷ answer is 9 if it's - answer is -70
4 0
2 years ago
Read 2 more answers
What is the equation in slope-intercept form of a line that is parallel to y=2x+5 and passes through the point (2, 8)?
trapecia [35]

Answer:

Step-by-step explanation:

y - 8 = 2(x - 2)

y - 8 = 2x - 4

y = 2x + 4

5 0
2 years ago
Read 2 more answers
We are stuck on this problem.
mezya [45]

Answer:

The measure of angle BED is 78°

Step-by-step explanation:

Hopefully you can see what I did there.

6 0
2 years ago
Describe situation in which a variable could be used to present any whole number greater than zero
Ira Lisetskai [31]
Well greater than zero can be anything above -1 so if u take a number and make something greater so comment any number above i will answer u and we will talk about it in the comment section

3 0
3 years ago
Other questions:
  • MiGuel ate 1/4 of a pizza in 1/2 of an hour. How long will it take Miguel to eat one pizza?
    9·2 answers
  • The chamber of commerce of a Florida Gulf Coast community advertises that area residential property is available at a mean cost
    5·1 answer
  • Factor.<br> 3n^4+21n^3+27n^2<br><br><br> Enter your answer in the box.
    8·1 answer
  • The deep end of a swimming pool is 15 meters. How deep is this in centimeter
    8·2 answers
  • Josephine has a rectangular garden with an area of 2x2
    14·2 answers
  • PLEASE HELP!! I will award 60 points!
    8·1 answer
  • Given: AB ≈ DC ; AC ≈ DB
    5·1 answer
  • 1. Mrs. Jones picks 3 flowers a day starting on Monday. How many does she have by Sunday?
    10·1 answer
  • tell me which 4 letters are correct! A? B? C? D? E? F? if you get them right i will give you brainliest!!
    6·1 answer
  • The perimeter of a rectangle measuring (2x + 2)cm by (3x -3) cm is 58cm. Calculate its area. 13. The perimeter
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!