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
Andrew [12]
3 years ago
13

Private colleges and universities rely on money contributed by individuals and corporations for their operating expenses. Much o

f tis moeny is put int a fund called an endowment, and the college spends only the interest earned by the fund. A recent survey of 8 private colleges in the United States revealed the following endowments (in millions of dollars): 60.2, 47.0, 235.1, 490.0, 122.6, 177.5, 95.4, and 222.0. Summary statistics yield X-bar (aka the mean)= 180.975 and S = 143.042.
a.) Calculate a 95% confidence interval for the mean endowment of all the private colleges in the United States assuming a normal distribution for the endowments.

b.) Calculate a 99% confidence interval for the mean endowment of all the private colleges in the United States assuming a normal distribution for the endowments.
Mathematics
1 answer:
bekas [8.4K]3 years ago
6 0

Answer:

Step-by-step explanation:

Given that private colleges and universities rely on money contributed by individuals and corporations for their operating expenses

A recent survey of 8 private colleges in the United States revealed the following endowments (in millions of dollars)

Mean = 180.975 and std dev s = 143.042

Assuming a normal distribution we have 95% critical value is 1.96 and 99% critical value is 2.58

a) 95% Conf interval = Mean ±1.96* std error

=(180.975-1.96(\frac{143.042}{\sqrt{8} } ,180.975+1.96(\frac{143.042}{\sqrt{8} })\\= (81.851, 280.098)

Since sample size is very small confidence interval is wider.

b) 99% Conf interval = Mean ±2.58* std error

=(180.975-2.58(\frac{143.042}{\sqrt{8} } ,180.975+2.58(\frac{143.042}{\sqrt{8} })\\= (50.50,311.45)

Since sample size is very small confidence interval is wider.

You might be interested in
George and Riley are selling fruit for a school fundraiser. Customers can buy small boxes of oranges and large boxes of oranges.
worty [1.4K]

The cost of small box of oranges is $7.

The cost of large box of oranges is $13.

<u>Step-by-step explanation:</u>

It is given that,

3 small boxes of oranges and 14 large boxes of oranges for a total of $203.

11 small boxes of oranges and 11 large boxes of oranges for a total of $220.

Let us take,

  • The cost of small box of oranges = x
  • The cost of large box of oranges = y

<u>The system of equations are framed as :</u>

3x + 14y = 203  ---------(1)

11x + 11y = 220  ---------(2)

<u>To solve these equations for x and y values :</u>

Multiply equation (1) by 11 and equation (2) by 3

Subtract eq(2) from eq(1),

 33x + 154y = 2233

- <u>(33x + 33y = 660)  </u>

  <u>        121 y = 1573  </u>

⇒ y = 1573 / 121

⇒ y = 13

∴ The cost of large box of oranges is $13.

Substitute y=13 in the eq(1),

⇒ 3x + 14(13) = 203

⇒ 3x + 182 = 203

⇒ 3x = 203 - 182

⇒ 3x = 21

⇒ x = 21 / 3

⇒ x = 7

∴ The cost of small box of oranges is $7.

<u />

7 0
3 years ago
In a city, 60% of the residents live in houses and 40% of the residents live in apartments. Of the people who live in houses, 20
Step2247 [10]
75%; so if we say there are 100 people in this city that means 60 of them live in houses and 40 of them live in apartments. Of the 60 living in houses 20% of them (12% of total population; 60 x .20) own their own business and those in apartments (40) 10% of them (4% of total pop.; 40 x .10) have their own business. In total 16 of the 100 people have businesses and 12 of those people live in houses so 12/16 equals .75. We multiply this by 100 to get the percent so there’s 75% that a person who owns a business in this city will also live in a house.
6 0
3 years ago
For what values of x is x2+2x=24 true?
JulijaS [17]

Answer:

x=-6 and x=4

Step-by-step explanation:

We must solve the quadratic equation to find the values of x that satisfy equality

x^2+2x=24

Subtract 24 on both sides of equality

x^2+2x-24=24-24

x^2+2x-24=0

Now we factor the quadratic equation

Identify two numbers that when you add them you get as a result 2 and when you multiply them you get as a result -24

The numbers sought are: 6 and -4

So the factors are:

(x+6)(x-4)=0

Finally note that the solutions are:

x=-6 and x=4

5 0
3 years ago
Read 2 more answers
Suppose an airline policy states that all baggage must be box shaped with a sum of length, width, and height not exceeding 174 i
Leya [2.2K]

Answer:

The square-based box with the greatest volume under the condition that the sum of length, width, and heigth does not exceed 174 in is a cube with each edge of 58 in and a volume of 195112 in^{3}

Step-by-step explanation:

For this problem we have two constraints, that are as follows:

1) Sum of length, width, and heigth not exceeding 174 in

2) Lenght and width have the same measure (square-based box)

We know that volume is equal to the product of all three edges, and with the two conditions into account we have the next function:

V=(w^{2})(174-2w)\\V=174w^{2}-2w^{3}

The interval of interest of the objective function is [0, 87]

This problem requieres that we maximize the function that defines the volume. We start calculating the derivative of the function, wich is:

V'=348w-6w^{2} \\V'=(348-6w)(w)

We need to remember that the derivative of a function represents the slope of said function at a given point. The maximum value of the function will have a slope equal to zero.

So we find the value in wich the derivative equals zero:

0=(348-6w)(w)\\w_1=0\\w_2=348/6=58

The first value (w=0) will leave us with a 'height-only box', so the answer must be w=58 in

The value is between the interval of interest.

And, once we solve for the constraints, we have that:

Lenght = Width = Heigth = 58 in

Volume = 195112 in^{2}

8 0
3 years ago
100 5 90 10 80 15 70 next term in the sequence?
max2010maxim [7]

Answer:

20

Step-by-step explanation:

6 0
3 years ago
Other questions:
  • During a research​ experiment, it was found that the number of bacteria in a culture grew at a rate proportional to its size. At
    11·1 answer
  • Plz help thx appreciate
    10·1 answer
  • 100 POINTS PLEASE HELP ASAP!!!!
    7·1 answer
  • Name each polygon! Determine if it appears to be a regular or not regular
    6·1 answer
  • Select the correct answer. Which expression is equivalent to this polynomial? 9x^2 - 4
    9·1 answer
  • Help me with 4-6 please I needed this by today help me!!!
    6·1 answer
  • 5/6 divided by 1/12 equals?
    8·2 answers
  • What is the product of the binomials (4a – 1) and (2b + 3)?
    6·2 answers
  • Marking brainliest!!<br><br> What should I put for the second question? I am confused. HELPP
    13·2 answers
  • How many cards are in a standard deck of cards? What are their colors?
    7·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!