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
dusya [7]
3 years ago
12

Assume, for the sake of this question, that the data were collected through a well-designed, well-implemented random sampling me

thod. The marketing department of a widget manufacturer collected potential consumer preference data regarding a proposed widget upgrade. Three hundred thirty-eight of 575 respondents reported preferring the proposed new widget. The widget manufacturing company had established a threshold of 60% preferring the proposed new widget to move forward with producing the new widgets. At a .10 level of significance, was the threshold probably met
Mathematics
1 answer:
amid [387]3 years ago
3 0

Answer:

Since the pvalue of the test is 0.2743 > 0.1, the threshold probably was met.

Step-by-step explanation:

The widget manufacturing company had established a threshold of 60% preferring the proposed new widget to move forward with producing the new widgets.

This means that at the null hypothesis we test if the proportion is at least 60%, that is:

H_{0}: p \geq 0.6

And the alternate hypothesis is:

H_{a}: p < 0.6

The test statistic is:

z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}

In which X is the sample mean, \mu is the value tested at the null hypothesis, \sigma is the standard deviation and n is the size of the sample.

0.6 is tested at the null hypothesis:

This means that:

\mu = 0.6

\sigma = \sqrt{0.6*0.4}

Three hundred thirty-eight of 575 respondents reported preferring the proposed new widget.

This means that n = 575, X = \frac{338}{575} = 0.5878

Value of the test-statistic:

z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}

z = \frac{0.5878 - 0.6}{\frac{\sqrt{0.6*0.4}}{\sqrt{575}}}

z = -0.6

Pvalue of the test and decision:

We want to find the probability of a proportion of 0.5878 or lower, which is the pvalue of z = -0.6.

Looking at the z-table, z = -0.6 has a pvalue of 0.2743.

Since 0.2743 > 0.1, the threshold probably was met.

You might be interested in
Solve for the variable <br>3(h - 9) =36
Diano4ka-milaya [45]
3h - 27 = 36
3h = 63
h = 21
6 0
3 years ago
What happens to the decimal point when we multiply a whole number by 100?
baherus [9]
There is a similar shortcut for multiplying decimal numbers by numbers such as 10, 100, and 1000: Move the decimal point to the right as many places as there are zeros in the factor. Move the decimal point one step to the right (10 has one zero). Move the decimal point two steps to the right (100 has two zeros).
3 0
2 years ago
Read 2 more answers
Find the appropriate rejection regions for the large-sample test statistic z in these cases. (Round your answers to two decimal
Usimov [2.4K]

Answer:

a) We have that the significance is given by \alpha =0.01 and we know that we have a right tailed test.

So for this case we need to look in the normal standard dsitribution a critical value that accumulates 1% of the area on the right and 99% of the area on the left. This value can be founded with the following excel code:

"=NORM.INV(1-0.01,0,1)"

And we got for this case z_{crit}=2.33

So then the rejection region would be z>2.33

b) We have that the significance is given by \alpha =0.05, \alpha/2 =0.025 and we know that we have a two tailed test.

So for this case we need to look in the normal standard dsitribution a critical value that accumulates 2.5% of the area on the right and 97.5% of the area on the left. This value can be founded with the following excel code:

"=NORM.INV(1-0.025,0,1)"

And we got for this case z_{crit}=\pm 1.96

So then the rejection region would be z>1.96 \cup z

Step-by-step explanation:

Part a

We have that the significance is given by \alpha =0.01 and we know that we have a right tailed test.

So for this case we need to look in the normal standard dsitribution a critical value that accumulates 1% of the area on the right and 99% of the area on the left. This value can be founded with the following excel code:

"=NORM.INV(1-0.01,0,1)"

And we got for this case z_{crit}=2.33

So then the rejection region would be z>2.33

Part b

We have that the significance is given by \alpha =0.05, \alpha/2 =0.025 and we know that we have a two tailed test.

So for this case we need to look in the normal standard dsitribution a critical value that accumulates 2.5% of the area on the right and 97.5% of the area on the left. This value can be founded with the following excel code:

"=NORM.INV(1-0.025,0,1)"

And we got for this case z_{crit}=\pm 1.96

So then the rejection region would be z>1.96 \cup z

7 0
3 years ago
On a prepaid plan, phone company A charges $76.00 for 500 minutes, and phone
sweet [91]

Answer:

Company B

Step-by-step explanation:

A is $0.15/min

   because 76/500

B is $0.12/min

  because 54/450

Company B is cheaper so it would be the better deal

7 0
3 years ago
Find the point (,) on the curve =8 that is closest to the point (3,0). [To do this, first find the distance function between (,)
ELEN [110]

Question:

Find the point (,) on the curve y = \sqrt x that is closest to the point (3,0).

[To do this, first find the distance function between (,) and (3,0) and minimize it.]

Answer:

(x,y) = (\frac{5}{2},\frac{\sqrt{10}}{2}})

Step-by-step explanation:

y = \sqrt x can be represented as: (x,y)

Substitute \sqrt x for y

(x,y) = (x,\sqrt x)

So, next:

Calculate the distance between (x,\sqrt x) and (3,0)

Distance is calculated as:

d = \sqrt{(x_1-x_2)^2 + (y_1 - y_2)^2}

So:

d = \sqrt{(x-3)^2 + (\sqrt x - 0)^2}

d = \sqrt{(x-3)^2 + (\sqrt x)^2}

Evaluate all exponents

d = \sqrt{x^2 - 6x +9 + x}

Rewrite as:

d = \sqrt{x^2 + x- 6x +9 }

d = \sqrt{x^2 - 5x +9 }

Differentiate using chain rule:

Let

u = x^2 - 5x +9

\frac{du}{dx} = 2x - 5

So:

d = \sqrt u

d = u^\frac{1}{2}

\frac{dd}{du} = \frac{1}{2}u^{-\frac{1}{2}}

Chain Rule:

d' = \frac{du}{dx} * \frac{dd}{du}

d' = (2x-5) * \frac{1}{2}u^{-\frac{1}{2}}

d' = (2x - 5) * \frac{1}{2u^{\frac{1}{2}}}

d' = \frac{2x - 5}{2\sqrt u}

Substitute: u = x^2 - 5x +9

d' = \frac{2x - 5}{2\sqrt{x^2 - 5x + 9}}

Next, is to minimize (by equating d' to 0)

\frac{2x - 5}{2\sqrt{x^2 - 5x + 9}} = 0

Cross Multiply

2x - 5 = 0

Solve for x

2x  =5

x = \frac{5}{2}

Substitute x = \frac{5}{2} in y = \sqrt x

y = \sqrt{\frac{5}{2}}

Split

y = \frac{\sqrt 5}{\sqrt 2}

Rationalize

y = \frac{\sqrt 5}{\sqrt 2} *  \frac{\sqrt 2}{\sqrt 2}

y = \frac{\sqrt {10}}{\sqrt 4}

y = \frac{\sqrt {10}}{2}

Hence:

(x,y) = (\frac{5}{2},\frac{\sqrt{10}}{2}})

3 0
3 years ago
Other questions:
  • What is the area of triangle with base 5m and height 12m
    15·1 answer
  • The sum of two numbers is 44 . the larger number is 12 more than the smaller number. what are the numbers?
    13·1 answer
  • Ricardo is 3 years older than Courtney. In 5 years the sum of their ages will be 81. How old is Ricardo now?
    7·1 answer
  • Maria will spin the arrow on the spinner three times. What is the probability that the arrow will stop on A, then B, then C?
    8·1 answer
  • Who can help me with 5 math questions ? yes or no, and i will give them to you.
    12·1 answer
  • there are three source of resistance in parallel circuit. Two of them are rated at 20 ohms, the other at 10 ohms. What is the ci
    15·1 answer
  • 20 to 25 percent change
    11·2 answers
  • FIND TWO NUMBERS WHOSE SUM IS 21 AND DIFFERENCE IS 17<br><br>11 , 10<br>2 ,23<br>19 ,2​
    6·1 answer
  • Both copy machines reduce the dimensions of images that are run through the machines. Which statement is true about the results
    15·2 answers
  • To make a specific hair dye, a hair stylist uses a ratio of 1 oz of red tone, oz of gray
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!