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
Fantom [35]
3 years ago
7

It is known that a particular laboratory task takes the average person 2.5 seconds (the variance is not known). 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 mean time was 2.7 seconds, with an estimated population standard deviation of 1.4 seconds. What should the researcher conclude?
Mathematics
1 answer:
madreJ [45]3 years ago
8 0

Complete Question

It is known that a particular laboratory task takes the average person 2.5 seconds (the variance is not known). 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 mean time was 2.7 seconds, with an estimated population standard deviation of 1.4 seconds. What should the researcher conclude? (Use the .05 significance level and use the five steps of hypothesis testing.)

Answer:

The researchers  conclusion is  

   There is no sufficient evidence to show that  older people are slower at the laboratory task    

Step-by-step explanation:

From the question we are told that

   The mean time is  \mu = 2.5 \ seconds

    The sample size is  n  =  30

    The  sample mean is  \= x  =  2.7 \  seconds

      The  standard deviation is  \sigma =  1.4 \  seconds

      The level of significance is  \alpha = 0.05

The null hypothesis is  H_o  :  \mu = 2.5

The alternative hypothesis is  H_a  :  \mu >  2.5

Generally the test statistics is mathematically represented as

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

=>  z = \frac{2.7   - 3 }{ \frac{1.4}{\sqrt{30} } }

=>  z =0.78

From the z table  the area under the normal curve to the right  corresponding to  z =0.78   is  

        p-value  = P(Z > 0.78) = 0.2177

From the value obtained we see that the p-value  > \alpha

   The decision rule is  

Fail to reject the null hypothesis

    The conclusion is  

There is no sufficient evidence to show that the older people are slower at the laboratory task  

You might be interested in
The radius of star A is 6.9203x10^5 km, which is 108.7 times the rafius of star B. what is the radius of the star B?
Kay [80]

Answer:

6366.4213

Step-by-step explanation: 6.9203x10^5 is 692,030. I divided 692,030 by 108.7 to get the answer. Anybody can correct any error I may have.

7 0
2 years ago
HELPPPPPPP!!!!!!!! I have been asking these questions and I am stuckkkkkk
zlopas [31]

Answer:

really <em> </em><em>o</em><em>h</em><em>.</em><em>.</em><em> </em><em>s</em><em>o</em><em>r</em><em>r</em><em>y</em><em> </em><em>d</em><em>u</em><em>d</em><em>e</em><em />

6 0
2 years ago
AACB = ADCE. If<br> AC = 5 and BC = 7<br> CD = [ ? ).<br> PLS HELP LOL PLS
FromTheMoon [43]

Answer:

CD = 5

Step-by-step explanation:

AC = 5

BC = 7

∆ACB ≅ ∆DCE, therefore,

AC = CD,

BC = CE, and,

AB = DE

Thus,

AC = CD = 5

CD = 5

6 0
3 years ago
Pleas help you'll git 30 points
Mandarinka [93]

Answer:

the answer would be A.

Step-by-step explanation:

because the number of books(n) times 2, because they have twice the number of books divided hy fifteen so fifteen is below the line. im bad at explaning trust me

4 0
3 years ago
What is the solution to the equation log2 (5x - 2) = 3?
Advocard [28]

From log BNE to BEN

X=2

if you want explaination then ask me

4 0
3 years ago
Other questions:
  • Solve for x 3/2(x-6)=-3
    11·1 answer
  • What is the first step when solving this equation for t?
    15·2 answers
  • The market value of Bryan's home is $389,000. The assessed value is $312,000. The annual property tax rate is $18.60 per $1,000
    7·1 answer
  • What is the equation of the line with a y-intercept of −10 and a slope of 3
    6·1 answer
  • Connor had 37 green marbles. Then he bought 3 bags of blue marbles. There were 6 marbles in each bag. How many marbles does Conn
    14·1 answer
  • Say you have (-4,-4) and (8,4)<br> which ones are the y2, y1, x2, and x1
    15·1 answer
  • How many factors for 25
    8·2 answers
  • URGENT!!!!!<br> What is the value is x?<br> A. 5.375<br> B. 5.5<br> C. 11<br> D. 13
    12·2 answers
  • There are 60 students in a class. Girls make up 20% of the class and 45% of them have phones. How many girls in the class have p
    5·1 answer
  • Liz is using the distributive property to evaluate the expression 27 (36) by using friendlier numbers. Her work is shown below.
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!