It is known that a particular laboratory task takes the average person 2.5 seconds. A researcher was interested in whether older people are slower (take longer) on this task. The researcher tested 30 randomly selected 80-year-olds. Their meantime was 2.7 seconds, with an estimated population standard deviation of 1.4 seconds. What should the researcher conclude (use the .05 level)?

Answers

Answer 1

Answer:

 The decision rule is  

Fail to reject the null hypothesis

  The conclusion is

 There is no sufficient evidence to conclude that older people are slower

Step-by-step explanation:

From the question we are told that  

    The average time taken is  [tex]\mu = 2.5 \ seconds[/tex]

      The  sample size is  [tex]n = 30[/tex]

     The sample mean is  [tex]\= x = 2.7 \ seconds[/tex]

      The standard deviation is  [tex]\sigma = 1.4 \ seconds[/tex]

The null hypothesis is  [tex]H_o: \mu = 2.5[/tex]

The alternative hypothesis  is  [tex]H_a : \mu > 2.5 \ seconds[/tex]

Generally the test statistics is mathematically represented as

                [tex]z = \frac{\= x - \mu }{ \frac{\sigma }{ \sqrt{n} } }[/tex]

=>              [tex]z = \frac{ 2.7 -2.5 }{ \frac{1.4}{ \sqrt{30} } }[/tex]

=>              [tex]z = 0.7825[/tex]

From the z table  the area under the normal curve to the right corresponding to  0.7825   is  

                [tex]p-value = P(Z > 0.7825 ) = 0.21696[/tex]

So from the question we see that the [tex]p-value > \alpha[/tex] hence

 The decision rule is  

Fail to reject the null hypothesis

  The conclusion is

 There is no sufficient evidence to conclude that older people are slower


Related Questions

In the expression g×h, g and h are real numbers. For what values of g and h is the expression g×h negative?

Select TWO that apply.


A. g=−1; h=−1

B. g=−1; h=1

C. g=1; h=−1

D. g=0; h=1

E. g=−1; h=0

Answers

Answer:

A

Step-by-step explanation:

They are both negative and that helps it.

Hope this helps!!!

The  values of g and h to make the expression g×h negative are g=−1; h=1 and g=1; h=−1.

What is Expression?

An expression is combination of variables, numbers and operators.

The given expression is g×h where g and h are real numbers

The expression g×h is negative when either g or h is negative.

Since multiplying two negative numbers results in a positive number

The only way for the expression to be negative is if one of the numbers is negative and the other is positive.

So when g=−1 and h=1

The expression  g×h = -1×1 = -1.

when g=1 and h=-1

The expression  g×h = 1×-1 = -1.

Hence,  g=−1; h=1 and g=1; h=−1 are the  values of g and h to make the expression g×h negative

To learn more on Expressions click:

https://brainly.com/question/14083225

#SPJ3

Find the mssing value.
I = ? , P = $250.00, r = 4%, t = 2 years

Answers

Answer:

20 I think

Step-by-step explanation:

I mean I would say it is 20

solve (x – 3)2 = 81 quadratic equation​

Answers

Answer:

x = 43.5 or x = 87/2

Step-by-step explanation:

(x - 3)2 = 81

2x - 6 = 81

2x = 87

x = 43.5

Simplify.
2 + 8h + 5 + 2h =

Answers

Answer: 7+10h=

Step-by-step explanation:

Just add the numbers that match.

2+5= 7

8h+2h= 10h

Answer:

Step-by-step explanation:

2+8h +5 2h =7+ 10h

You add 2+5 and then add 8h and 2h

Determine a constant in 9x + 4y -13.
A) -13
B) 9x
C) 4y

Answers

I think the answer is c

How many quadrants are included on the coordinate plane?

Answers

Four, they are labeled clock wise 1,2,3,4

Answer:

There are 4

Step-by-step explanation:

You have the 1st 2nd 3rd and 4th quadrant.

They go from top right to top left then bottom left then to bottom right.

Simplify (10x^3 -3x-5) - (7x^2 +4x-9)​

Answers

Answer:

10x³ - 7x² - 7x + 4

General Formulas and Concepts:

Pre-Algebra

Distributive Property

Algebra I

Combining Like Terms

Step-by-step explanation:

Step 1: Define

(10x³ - 3x - 5) - (7x² + 4x - 9)

Step 2: Simplify

Distribute negative:                    10x³ - 3x - 5 - 7x² - 4x + 9Combine like terms (x):               10x³ - 7x² - 7x - 5 + 9Combine like terms (Z):              10x³ - 7x² - 7x + 4

while tim is waiting for school to start he pulls a quarter from his pocket. how many outcomes are possible if he flips the quarter three times?​

Answers

Answer:

3

Step-by-step explanation:

he flips it three times

Gina popped 7 times as many balloons as Sam did. If Sam popped n balloons, how many balloons did Gina pop?
O A 7-n
7n
O c 7+1
o

Answers

Answer:

B. 7n

Step-by-step explanation:

Gina popped 7 times more than Sam, the keyword is times, so u have to multiply the amount of balloons Sam poppes, n, with 7

If it said Gina popped 7 balloons more, then it would be 7 + n

Given ac=46 and the picture above

1.find x
2.find ab
3.find bc

I will give brainlist

Answers

Answer:

x = 5, AB = 27, BC = 19

Step-by-step explanation:

From the diagram

AB + BC = AC , substitute values

4x + 7 + 3x + 4 = 46 , that is

7x + 11 = 46 ( subtract 11 from both sides )

7x = 35 ( divide both sides by 7 )

x = 5

Thus

AB = 4x + 7 = 4(5) + 7 = 20 + 7 = 27

BC = 3x + 4 = 3(5) + 4 = 15 + 4 = 19

Answer:

1. x = 5

2. AB= 27

3. BC = 19

Step-by-step explanation:

Solving for X:

The entire segment is 46. Parts AB and BC make up the whole thing. So, to find x, add both expressions and set them equal to 46.

4x+7+3x+4=46 (combine like terms)

7x+11=46 (subtract 11 from both sides)

7x = 35 (divide by 7)

x = 5

Finding AB:

Plug 5 in for x and evaluate the expression.

4(5)+7

20 + 7= 20

AB is 27

Finding BC:

Plug in 5 for x and evaluate the expression.

3(5)+4

15+ 4=19

Check your work.

Add the values of AB and BC to make sure they add up to 46, which is AC.

27 + 19 = 46, so this is correct.

Write an equivalent ratio that is triple 7 to 11

Answers

Answer:

21/33

Step-by-step explanation:

Multiply both numbers by 3

What are the coefficients in the algebraic expression

Answers

There is no picture or anything. Need more information

Please answer this :)

Answers

Answer:

one option could be for the first box 5 and 9 and in the next box 15 and 27 bc u can scale factor it by 3

Step-by-step explanation:

Write a subtraction fact that will give the same difference as 15-7.

Answers

Answer:

9-1

Step-by-step explanation:

Well, 15-7 is 8. We can create an simple subtraction problem for this such as...

9-1=8

I hope this helped....have a nice day ❤

Adults in Turkey have mean caloric intake of 3500 calories per day (Wikipedia) with a standard deviation of 500 calories. A sample of 25 Ankara University students has an average intake of 3400 calories per day. Is this enough evidence to conclude that Ankara U. students average is not 3500 calories per day? Assume the distribution is normal.
A. State the null and alternative hypotheses.
B. What is the value of the test statistic?
C. Specify the rejection region?
D. State the conclusion.

Answers

Answer:

A) Null hypothesis; H0: μ = 3500

Alternative hypothesis;Ha μ ≠ 3500

B) t = -1

C) the rejection region will be;

p-value < 0.05

D) Conclusion is that there is no sufficient evidence to support the claim that Ankara U. students average is not 3500 calories per day.

Step-by-step explanation:

We are given;

Population mean; μ = 3500

Population standard deviation; σ = 500

Sample mean; x¯ = 3400

Sample size; n = 25

We want to find enough evidence to conclude that Ankara U. students average is not 3500 calories per day.

Thus, the hypothesis is defined as;

A) Null hypothesis; H0: μ = 3500

Alternative hypothesis;Ha μ ≠ 3500

B) sample size is less than 30, thus we will use a t-test.

Formula for the test statistic is;

t = (x¯ - μ)/(σ/√n)

t = (3400 - 3500)/(500/√25)

t = -100/(500/5)

t = -1

C) since the sample is small, let's assume a significance level of 0.05.

Thus,the rejection region will be;

p-value < 0.05

D) from online p-value from t-score calculator attached using;

t = - 1; DF = 25 - 1 = 24; significance level = 0.05 and two tailed hypothesis, we have;

p-value ≈ 0.3273

This is greater than the significance value of 0.05.

Thus, we will fail to reject the null hypothesis and conclude that there is no sufficient evidence to support the claim that Ankara U. students average is not 3500 calories per day.

A football team gained 9 yards on one play and then lost 22 yards on the next and
finally gained 12 yards on the final play. What is the result of the three plays?

Answers

9 - 22 is -13 then add 12 yards equals -1 so they just lost one years from where they started so the answer is -1

Question is in the image​

Answers

Answer:

4.

Step-by-step explanation:

y = -2x + 3

-1 = -2(2) + 3

-1 = -4 + 3

-1 = -1

y = x - 3

-1 = 2 - 3

-1 = -1

Evaluate: 3.2^t when t = 4 *

Answers

Answer:

48

Step-by-step explanation:

In pemdas, powers and roots always come first

3 * 2^t

3 * 2^4

3 * 16

Then simplify the rest

48

What's is the quotient?

-4 1/3
____
-3/4
Thank you please answer​

Answers

Answer:

iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii

Step-by-step explanation:

Answer:

 5 7/9 (5 and 7/9)

Step-by-step explanation:

-4 1/3 divided by -3/4

= (-4 1/3)  / ( -3/4)

= (-13/3) / (-3/4)

= (-13/3) * (-4/3)

= 52/9

= 5 7/9

#1. please help me with my math Select All

Answers

Answer:

B.) - ⅖ -⁴⁄₃ᵖ and

D.) -⁴⁄₃ᵖ + (- ⅖)

Step-by-step explanation:

-⁴⁄₃ᵖ - ⅖ is equivalent to - ⅖ -⁴⁄₃ᵖ and -⁴⁄₃ᵖ + (- )

Thus, The answer is - ⅖ -⁴⁄₃ᵖ and -⁴⁄₃ᵖ + (- ⅖)

-TheUnknownScientist

Need help please on this

Answers

Answer:

I think it's dilated by a scale factor of 5. Because the black one is 3 squares long and the purple one is 15. So divide those and you get 5! and to check just multiply 5x3 to find the length of the purple one!

Step-by-step explanation:

Hope this helps! please mark brainliest! :)

Which expression is equivalent to 3(5 + 4)?

Answers

Answer:

3 ( 5 + 6 ) = 15 + 18

Step-by-step explanation:

Sorry if wrong but if right can you mark me brainiest

Answer: 15 + 12

Reason: You just distribute the three to five and four, and you get an equivalent equation to 3(5 + 4)

I hope this helps, and Happy Holidays! :)

ANSWER FAST PLZ
find the height of a cone with a diameter of 12m whose volume is 113m3
A.2m
B.1m
C.9m
D.3m

Answers

Answer:

I'm pretty sure it's 3

Step-by-step explanation:

h=3(V/πr2)

I just plugged it into this equation

Helppp please i need helppppppppoooo

Answers

Answer
A)

Explanation


Answer:

The answer would be A.

Fun Fact - Cats have fewer toes on their back paws.

Like most four-legged mammals, they have five toes on the front, but their back paws only have four toes. Scientists think the four-toe back paws might help them run faster.

12. Write the equation of a line that passes through point (2,3) and is parallel
to the line 6x + 3y = 12. *

Answers

Is going to be 3/3 and I did this

PLZ HELP if u know the amswer​

Answers

Answer:

The correct answer is the last option (d.)

Step-by-step explanation

The answer is 1over15x(19x-81)

Dan, David, Thor, and Charles together clean out evil from 60 cities. Dan cleaned up 0.25 of the cities, David cleaned up 12 of the 60 cities, Thor cleaned 35% of the cities, and Charles cleaned up the remaining cities. Who cleaned up the most cities? (5 points)

a. Dan
b. David
c. Thor
d. Charles

Answers

Answer:

d. Charles cleaned the most cities

Find the value of the missing angle in the triangle below:

Answers

Answer:

85°

Step-by-step explanation:

x+32°+63°=180°(being sum of interior angle of triangle)

x=180°-95°

:. x=85°

What is the difference of the polynomials?
(5x^3+ 4x^2)-(6x^2-2x-9)

Answers

i think its B ......

The difference of the polynomials (5x3 + 4x2) – (6x2 – 2x – 9) is 5x3 – 2x2 + 2x + 9.

A polynomial is an expression consisting of variables and coefficients,

5x3 + 4x2 - (6x2 - 2x - 9)

= 5x3 + 4x2 - 6x2 + 2x + 9

= 5x3 - 2x2 + 2x +

5.00 minus2.40minus1.33= plz show me how you got that answer step by step

Answers

Answer:

5.00 -2.40= 2.60

2.60-1.33= 1.27

The answer is 1.27

Step-by-step explanation:

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