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
vlada-n [284]
2 years ago
7

A random sample is taken and the sample size is 25. the sample is normally distributed, the sample mean is 80, and the standard

deviation is 5.5. find a 90% confidence interval for the population mean.
Mathematics
1 answer:
torisob [31]2 years ago
7 0

The 90% confidence interval for the population mean is 78.1905<x<81.8095

<h3>Confidence interval</h3>

The formula for calculating the confidence interval is expressed as:

CI = x ± z*s/√n

Given the following parameters

mean "x" = 80

z = 1.645

s = 5.5

n = 25

Substitute

CI = 80 ± 1.645*5.5/√25

CI = 80 ± 1.8095

CI = {78.1905, 81.8095}

Hence the 90% confidence interval for the population mean is 78.1905<x<81.8095

Learn more on confidence interval here: brainly.com/question/2141785

#SPJ1

You might be interested in
Hey guys I need help with this maths problem thank you.
Nataly_w [17]

Answer:

Step-by-step explanation:

(a) radius is the bottom leg of the right triangle formed by the slopped edge and the vertical line from the tip to the center of the base.  So that's easy enough with the pythagorean theorem.

15^2 + b^2 = 34^2

b = sqrt(1156 - 225)

b = 30.512

(b) The surface area can be looked at as the surface area of the circular base + the surface area of the actual cone.

area of a circle is pi*r^2 and the surface area of the cone, excluding the base,  is pi*r*s, where s is the slant height.  If you want to know where that one comes from  it kinda takes some calculus to understand but I can link a video to explain it.

pi*r^2 + pi*r*s

pi(r^2+rs) I factored out pi to make things a little easier.

pi(931+30.512*34)

1968.408pi  Feel free to multiply out pi.

(c) Volume for a cone (or any kind of pyramid) is area of the base times the height all divided by 3.

so since we know the area of the base we can just plug in.

(pi*r^2*h)/3

(pi*931*15)/3

4655pi

4 0
4 years ago
Find the missing side lengths.<br><br> Need help please.
gizmo_the_mogwai [7]

Answer:

the answer is 30

you do :

90+60=150

180-150=30

7 0
3 years ago
Read 2 more answers
Find the standard form of the equation of the parabola with a focus at (0, -3) and a directrix at y = 3. (5 points)
OLEGan [10]

Answer:

From given option ,  the equation of parabola is                                            y = negative x² divided by 12

Step-by-step explanation:

Given as for parabola :

The focus is at (0 , - 3)

The directrix equation is y = 3

Now, equation of parabola parallel to y-axis is

( x - h )² = 4 p ( y - k )

where focus is ( h , k+p )   and  directrix equation is y = k - p

So, from equation

h  = 0     and   k + p = - 3

And y = k - p   i.e k - p = 3

Now solving  ( k + p ) + (  k - p ) = - 3 + 3

or, 2 k = 0  ∴ k = 0

Put the value of k , k + p = - 3

So, 0 + p = - 3    ∴ p = - 3

Now equation of parabola with h = 0  , k = 0  , p = - 3

( x - h )² = 4 p ( y - k )

I.e ( x - 0 )² = 4 × ( - 3 ) ( y - 0 )

Or, x² = - 12 y   is the equation of parabola

Hence  From given option ,  the equation of parabola is                                y = negative x² divided by 12       Answer

7 0
3 years ago
Help pls this is for my math test.
ella [17]

Answer:

I think 1st option is correct

4 0
3 years ago
Read 2 more answers
What is 67.142 rounded to the nearest ones?
Nezavi [6.7K]
67.142 rounded to the nearest ones is 67 cause the .1 is not .5 or greater.
8 0
3 years ago
Other questions:
  • What is the next number in the sequence? 9….3….1….1/3… 1/4 1/6 1/9 1/12 skip?
    8·1 answer
  • What is radio play ?
    9·2 answers
  • If the price index is 200, how much did a $12 pizza (today) cost in the base year? question 9 options:
    6·1 answer
  • Greg is training for the upcoming basketball season. His schedule this week allows him to complete at most 8 training sessions.
    11·1 answer
  • If y=-x+1 and y=3x+1, what is the numerical value of (3x+y)
    15·1 answer
  • 3.24 repeating as a fraction
    12·2 answers
  • Write the decimal equivalent of 35/99
    9·1 answer
  • This is the last question i got a 100 so far can we get a full 100
    5·1 answer
  • PLEASEE HELP AND SHOW WORK​
    5·1 answer
  • ANSWER THIS TO GET 23 POINTS AND BRAINLIEST
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!