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
aliina [53]
3 years ago
7

25 scores from all of the students who took the test. She sees that the mean score is 134 with a standard deviation of 6.0547. T

he superintendant wants to know if the standard deviation has changed this year. Previously, the population standard deviation was 13. Is there evidence that the standard deviation of test scores has decreas
Mathematics
1 answer:
Tomtit [17]3 years ago
7 0

Answer:

WE fail to reject the Null and conclude that ; Standard deviation of test hasn't decreased.

Step-by-step explanation:

The hypothesis :

H0 : σ = 13

H1 : σ < 13

Using the Chisquare Square statistic :

χ² = (n-1)*s²/σ²

Sample size, n = 25

s² = 6.0547²

σ² = 13²

χ² = (25 - 1)*6.0547² / 13²

χ² = 879.82541016 / 169

χ² = 5.206

The degree of freedom, df = 25 - 1 = 24

The Pvalue(5.206, 24) = 0.99981

Reject H0, if Pvalue < α ;

Since Pvalue > α ; WE fail to reject the Null and conclude that ; Standard deviation of test hasn't decreased.

You might be interested in
An item is regularly priced at $70. It is on sale for 70% off the regular price. What is the sale price?
Arada [10]

Answer:

$21

Step-by-step explanation:


7 0
3 years ago
Plssss answer! Your team is renting a photo booth for the 8th grade dance, but you have to buy the photo paper and other supplie
Rama09 [41]

Answer:

$215.25

Step-by-step explanation:

4 0
3 years ago
Café Noir charges a 1% levy on the bill for trading on Sundays. If the final bill is $55.55, what was the original price, taking
svetoff [14.1K]
As I guess I think its 5
7 0
3 years ago
A study of the effects of color on easing anxiety compared anxiety test scores of participants who completed the test printed on
NikAS [45]

Answer:

Step-by-step explanation:

To solve this, we would follow these simple steps. We have

unvrs :

The arithmetic mean, x-bar for the yellow paper group (Y) = 20.6

The arithmetic mean, x-bar for the green paper group (G) = 21.75

Recall that, H0: µY = µG

And from the data we have, we can see that

H0: µY< µG

We proceed to say that the

T-Test-statistic = -0.404

Also, the p-value: 0.349

From our calculations, we can see that the p-value > 0.05, and as such, we conclude that we will not reject H0. This is because there is not enough evidence to show that test that is printed on the yellow paper decreases anxiety at a 0.05 significance level.

6 0
3 years ago
peter drove a total of 1000 km and used 100 litre of prtrol calculate the rate of which the petrol was in kilometers per litre??
abruzzese [7]

Answer:

The petrol used was 0.1 litre for every 1 kilometre.

6 0
2 years ago
Other questions:
  • you take a test in which there are 249 points possible. The test consist of true or false questions worth two points each multip
    11·1 answer
  • At a height of about 212 meters, One Shell Square is the tallest building in New Orleans. Marlie is creating a scale model of th
    9·2 answers
  • In a class of 20 students the average age of all the students is 16 years. The oldest student exactly 16 year old . What us the
    8·1 answer
  • Por favor me pueden ayudar
    14·1 answer
  • What is the value of the expression below when z = 8 and w=<br> = 8?<br> 2z + 7w
    10·2 answers
  • 30 Points!!! What is the simplified form?
    11·2 answers
  • What’s the answer?????
    15·2 answers
  • Plzzzzzz heeelllpp. 20 pointsss
    12·2 answers
  • The ratio of violins two cellos is 8 to 3. If there are 24 violins, how many cellos are there?
    11·2 answers
  • Find the midpoint of the line segment shown below.
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!