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
Wewaii [24]
3 years ago
10

1. Find the 90% Cl for the population mean if sample

Mathematics
1 answer:
Elden [556K]3 years ago
8 0

Answer:

The answer is below

Step-by-step explanation:

1)

mean (μ) = 12, SD(σ) = 2.3, sample size (n) = 65

Given that the confidence level (c) = 90% = 0.9

α = 1 - c = 0.1

α/2 = 0.05

The z score of α/2 is the same as the z score of 0.45 (0.5 - 0.05) which is equal to 1.65

The margin of error (E) is given as:

E=Z_{\frac{\alpha}{2} }*\frac{\sigma}{\sqrt{n} } =1.65*\frac{2.3}{\sqrt{65} } =0.47

The confidence interval = μ ± E = 12 ± 0.47 = (11.53, 12.47)

2)

mean (μ) = 23, SD(σ) = 12, sample size (n) = 45

Given that the confidence level (c) = 88% = 0.88

α = 1 - c = 0.12

α/2 = 0.06

The z score of α/2 is the same as the z score of 0.44 (0.5 - 0.06) which is equal to 1.56

The margin of error (E) is given as:

E=Z_{\frac{\alpha}{2} }*\frac{\sigma}{\sqrt{n} } =1.56*\frac{12}{\sqrt{45} } =2.8

The confidence interval = μ ± E = 23 ± 2.8 = (22.2, 25.8)

You might be interested in
Please HELP!!!!
Karolina [17]

Answer:


Step-by-step explanation:

Firstly, note that -2i really is just z = 0 + (-2)i, so we see that Re(z) = 0 and Im(z) = -2.

When we're going from Cartesian to polar coordinates, we need to be aware of a few things! With Cartesian coordinates, we are dealing explicitly with x = blah and y = blah. With polar coordinates, we are looking at the same plane but with angle and magnitude in consideration.

Graphing z = -2i on the Argand diagram will look like a segment of the y axis. So we ask ourselves "What angle does this make with the positive x axis? One answer you could ask yourself is -90°! But at the same time, it's 270°! Why do you think this is the case?

What about the magnitude? How far is "-2i" stretched from the typical "i". And the answer is -2! Well... really it gets stretched by a factor of 2 but in the negative direction!

Putting all of this together gives us:

z = |mag|*(cos(angle) + isin(angle))

= 2*cos(270°) + isin(270°)).

To verify, let's consider what cos(270°) and sin(270°) are.

If you graph cos(x) and look at 270°, you get 0.

If you graph sin(x) and look at 270°, you get -1.

So 2*(cos(270°) + isin(270°)) = 2(0 + -1*i) = -2i as expected.

3 0
3 years ago
Need help test is due 3/10/18
Kazeer [188]
I believe <span>angle 1 is 115° </span>
8 0
3 years ago
Paul's bathtub is clogged. He has to empty 30 liters of water by hand. If Paul carries two buckets each trip, what combination o
mojhsa [17]

5 liter bucket with the 3 liter bucket twice, and then use the 3 liter bucket and the 4 liter bucket twice.

3 0
3 years ago
-2/5x - 1/2 + x = -40/11
IgorLugansk [536]

Answer: x = 6.56

Step-by-step explanation: -0.4x - 0.5 + x = 3.63

-0.4x^2 - 0.5 = 3.63

-0.4x^2 = 4.13

0.63x = 4.13

x = 6.56

7 0
2 years ago
Q7.
VLD [36.1K]

Answer:

10

Step-by-step explanation:

Let c = sum of ages of all children.

mean age of all children = c/15 = 7

c = 15 * 7 = 105

The sum of the ages of all children is 105.

Let b = sum of ages of the 9 boys.

mean age of boys = b/9 = 5

b = 9 * 5 = 45

The sum of the ages of the boys is 45.

The sum of the ages of the girls is c - b.

c - b = 105 - 45 = 60

The number of girls is 15 - 9 = 6

mean age of girls = (sum of ages of the girls)/(number of girls) =

= 60/6 = 10

3 0
3 years ago
Other questions:
  • A house painter charges $14 per hour for the first 45 hours he works, time and a half for the 10 hours after that, and double ti
    5·1 answer
  • Simplify 3r (r - 10s) - 4r (7s + 2r)
    10·2 answers
  • The length of a rectangle is 2 more than its width. If the area of the rectangle is 20m squared, what are the dimensions of the
    9·1 answer
  • The Anderson family is on a road trip. They're looking at a map (shown below) trying to figure out where to go next. Their car i
    6·1 answer
  • Taryn collected data for the rain collected over a number of days in various cities. Which of the data sets represents a scatter
    11·1 answer
  • Two different customers go to Vallarta to get stuff to make tacos. Customer A buys 2 packages of tortillas for $2 each, 2 pounds
    8·2 answers
  • HELP PLEASEEEEEEEE ASAPP
    8·2 answers
  • Help me find answer please very much lost and its a test:(((will give brainiest or w.e it is
    11·1 answer
  • PLS HELP ASAP
    12·1 answer
  • Find a function whose graph is a parabola with vertex (4,-5) and that passes through the point (2, 3).
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!