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
Harlamova29_29 [7]
3 years ago
14

The mean gross annual incomes of certified welders are normally distributed with the mean of $20,000 and a standard deviation of

$2,000. The ship building association wishes to find out whether their welders earn more or less than $20,000 annually. The alternate hypothesis is that the mean is not $20,000. If the level of significance is 0.10, what is the critical value?
1.65
1.28
±1.28
±1.65
Mathematics
1 answer:
masya89 [10]3 years ago
8 0

Answer:

Z=±1.65

Step-by-step explanation:

Some previous concepts

The p-value is the probability of obtaining the observed results of a test, assuming that the null hypothesis is correct.

A z-test for one mean "is a hypothesis test that attempts to make a claim about the population mean(μ)".

The null hypothesis attempts "to show that no variation exists between variables or that a single variable is no different than its mean"

The alternative hypothesis "is the hypothesis used in hypothesis testing that is contrary to the null hypothesis"

System of hypothesis

Null hypothesis: \mu=20000

Alternative hypothesis: \mu \neq 20000

If the random variable is distributed like this: X \sim N(\mu=20000,\sigma=2000)

The significance level provided is \alpha=0.1 and the value of \alpha/2= 0.05.

Since we are conducting a bilateral test, then we have two critical values. We need to find two quantiles that accumulates 0.05 of the area on the tails of the normal standard distribution. And in order to find it we can use the following excel codes:

"=NORM.INV(0.05,0,1)" , "=NORM.INV(1-0.05,0,1)"

And we got this:

z_{\alpha/2}=-1.65 and z_{1-\alpha/2}=1.65

So the correct answer for this case is:

Z=±1.65

You might be interested in
Multi step equation 12 threw 14 pls
slega [8]

The computation of the equation shows that the answers will be:

12. 340 units

13. 2(270) + (2 × x) = 690

14. x = 5

<h3>How to compute the equations?</h3>

12. The first equation that's given will be:

(13.50 × x) - (3.65 × x) = 3349

13.50x - 3.65x = 3349

9.85x = 3349

x = 3349/9.85

x = 340

The number to break even is 340 units

13. The equation that can be used to find the perimeter will be:

2(270) + (2 × x) = 690

540 + 2x = 690

2x = 690 - 540

2x = 150

x = 150/2 = 75

14. x + x + 2 + 8 = 20

2x + 10 = 20

2x = 20 - 10

2x = 10

x = 10/2

x = 5

Learn more about equations on:

brainly.com/question/2972832

#SPJ1

4 0
2 years ago
Read 2 more answers
Determine algebraically whether the function is even, odd, or neither even nor odd.
m_a_m_a [10]
For a function (fn) to be odd:
f(x) = - f(-x)
For a fn to be even:
f(x) = f(-x)
For a fn to be neither even nor odd
f(x) != f(-x)  [No Relation]

(-x)^n = x^n   for n -> even
(-x)^n = -x^n  for n -> odd
In your example:

f(x) = -4x^3 + 4x
f(-x) = -4 (-x)^3 + 4 (-x)^1  ( 3 and 1 are odd powers )
f(-x) = 4x^3 - 4x   (take -1 common to do the check)
f(-x) = -( -4x^3 + 4x ) = - f(x)  [between the bracket was the original fn]

f(x) = - f(-x)   
so the function is odd also called symmetric about the origin
7 0
3 years ago
A transformation maps a onto b and c onto d name the image of a name the preimage of b name the image of c name the preimage of
Doss [256]

If a transformation maps a \mapsto b, then b is the image of a, and a is the preimage of b. So,

  • the image of a is b
  • the preimage of b is a
  • the image of c is d
  • the preimage of d is c
7 0
3 years ago
What does the slope of graph show about the Hardware stores selling price for the rope?
SashulF [63]

Answer:

If the price is increasing or decreasing

Step-by-step explanation:

The slope is a visual representation of the cost over time.

3 0
2 years ago
Read 2 more answers
Casey paid $32 for a book that was on a sale at 20% off. What was the original price for that book?
Elis [28]

Answer:

$40

Step-by-step explanation:

If it was 20% off, you are paying 80% of the original price.

So .80 * Original price = $32

32/.8 = 40

8 0
3 years ago
Read 2 more answers
Other questions:
  • What is the value of x in simplest radical form ?
    11·1 answer
  • A home builder wants 5 5 acres of land split into 13 13 equal sections. Three of these expressions give the number of acres of l
    12·2 answers
  • A city manager wants to add a playground in a new city park. The rectangle below represents the plan for the dimensions of the r
    15·1 answer
  • Express the number 9067.5 in scientific notation to 4 significant figures.
    12·1 answer
  • What is 36% as a fraction and a decimal?
    13·2 answers
  • Question 2 of 10
    14·1 answer
  • Marci is going to use tile to cover her terrace. How much tile does she need?
    12·1 answer
  • -3*6<br> Multiplying and dividing integers
    15·1 answer
  • GEOMETRY TRIANGLES I WILL GIVE BRAINLIEST H
    5·1 answer
  • Expand then fully factorise 9(f + 3) +36f - 3)
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!