Researchers have noted a decline in cognitive functioning as people age (Bartus, 1990). However, the results from other research suggest that the antioxidants in foods such as blueberries can reduce and even reverse these age-related declines, at least in laboratory rats (Joseph et al., 1999). Based on these results, one might theorize that the same antioxidants might also benefit elderly humans. Suppose a researcher is interested in testing this theory. The researcher obtains a sample of adults who are older than 65, and gives each participant a daily dose of a blueberry supplement that is very high in antioxidants. After taking the supplement for 6 months, the participants are given a standardized cognitive skills test and produce a mean score of . For the general population of elderly adults, scores on the test average μ and form a normal distribution with σ=9.

(a)-Can the researcher conclude that the supplement has a significant effect on cognitive skill? Use a two-tailed

Complete Question

The complete question is shown on the first uploaded image

Answer:

a

Yes the researcher can  conclude that the supplement has a significant effect on cognitive skill

b

[tex]d =  0.5778 [/tex]

c

The result of this hypothesis test shows that there is sufficient evidence to  that the supplement had significant effect.The measure of effect size is  large due to the large value of Cohen's d (0.5778 > 0.30 )

Step-by-step explanation:

From the question we are told that

  The sample size is  n=16

    The sample mean is  [tex]M  =  50.2[/tex]

    The standard deviation is [tex]\sigma  = 9[/tex]

    The  population mean is  [tex]\mu =  45[/tex]

     The level of significance is  [tex]\alpha =  0.05[/tex]

The null hypothesis is [tex]H_o  \mu =45[/tex]

The alternative hypothesis is [tex]H_a  \mu \ne 45[/tex]

Generally the test statistics is mathematically represented as

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

=>       [tex]z =  \frac{50.2 - 45}{\frac{9}{\sqrt{16} } }[/tex]

=>       [tex]z =  2.31 [/tex]

Generally the p-value is mathematically represented as

     [tex]p-value  =  2 *  P(Z >  z )[/tex]

      [tex]p-value  =  2 *  P(Z >  2.31 )[/tex]

From the z-table  

      [tex]P(Z >  2.31 ) = 0.010444[/tex]

=>     [tex]p-value  =  2 *  0.010444 [/tex]

=>     [tex]p-value  =  0.021 [/tex]

From the obtained values we see that [tex]p-value <  0.05[/tex]

 Decision Rule

 Reject the null hypothesis

Conclusion

There is sufficient evidence to conclude that the supplement has a significant effect on the cognitive skill of elderly adults

Generally the Cohen's d for this study is mathematically represented as

    [tex]d =  \frac{M  -  \mu}{\sigma }[/tex]

=>  [tex]d =  \frac{50.2 -45}{9 }[/tex]

=>  [tex]d =  0.5778 [/tex]

you hear a pitch where the founder says he'll reach $30 million sales in 5 years. His first year sales are projected at $5 million. which is closest to the compound growth rate he is implying?

-10%
14%
56%
298%​

Explain how filing your tax return online can make payments easier.

1. (02.01 MC) Celine has a bottle that contains 20% milk and the rest water. The bottle has 1 liter of water. Part A: Write an equation using one variable that can be used to find the total number of liters of milk and water in the bottle. Define the variable used in the equation. (5 points) Part B: How many liters of milk are present in the bottle? Show your work. (5 points) (10 points)

Last year, 140 people in a community had cell phones. This year, the number
of people in the community with cell phones has increased by 65%.
A. Wat is the percent of increase?
65%
B. What is the change in the number of people with cell phones?
C. How many people in the community have cell phones this year?

Tom bought 2 pounds bananas for $3. How much would it cost for 5 pounds of bananas?

Which graph represents a function with a rate of change of 0.5?
5
1
-5 -4 -3 -2
4
5
Ty
5
4
3
2
1

9/2-12v=1/4
please explain how you got your awnser as well.

The supplementary angle of 57° is

. Which fraction has the greatest value?

5/9. 7/8. 12/17. 8/11

What is the midpoint between n(- 4, 4) and (- 2, 2)

will give free brainlyest
Answer the following question using a Collins Type 2 writing format:
Give 1-2 reasons how reading current event articles help us better understand geographic issues?

Convection currents in the Earths mantle are caused by (please dont guess or just say anything random for points)

A.) Less dense hot magma moving downward

B.) Less dense hot magma moving upward

C.)Tectonic plate movement

D.)More dense cooler magma moving upward ​

Which equation can be used to find T the number of tickets each class needs to sell so that the total amount raised is the same for both classes

Sal made 8 ft of sausage links on Friday morning. He used 4 ft for dinner service on Friday night. On Saturday morning, he made another 8 ft of sausage links and used 12 ft for dinner service Saturday night. What is the net change in the amount of sausage Sal had from Friday morning until after dinner service Saturday night?

8 out of every 20 spectators were girls. There were a total of 1560 spectators at the game. How many of the spectators were girls

“without using technology describe the end behavior of f(x) equals negative 3X to the 4th+ 7X squared -12 X +13” PLEASE HELP!!!!

2. The hamster, x, walked 20 feet. The guinea pig walked 1/4 less than that. The guinea
pig walked
feet

In City A, the temperature rises 7 degrees F from 8AM to 9AM. Then the temperature drops 6 degrees F from 9AM to 10AM. In City B, the temperature drops 2 degrees F from 8AM to 9AM. Then the temperature drop 4 degrees F from 9AM to 10AM. Write an expression that represents the change in temperature from 8AM to 10AM for each city. Simplify and interpret each sum.

Determine whether AB and MN are parallel, perpendicular, or neither.
Graph each line to verify your answer: A(-1,4), B(2.-5), M(-3,2). N(3, 0)

If u place a 13 foot ladder against a 12 foot building,how many feet will the Ladder be from the building

Helppppp! I dot know the answer

A case of soda has 24 cans in it. There are 12 cases of soda. 1) What is the total number of cans of soda there are? 2) The soda is donated to 7 (seven) teams. How many cans of soda does each team get? {include remainder}

2000: $2.50 2015: $2.00 what is the percent of change in cost.

PLEASE HELP f(x)= x-2. Find the inverse of f(x)

Find f'(a)/ f(x)=[tex]\sqrt{2-2x}[/tex]

Taxi A charges $3.00 plus $0.30 for every
mile.
Taxi B charges $3.25 plus $0.20 for every mile.
How much money, in dollars, does Kelly save by using Taxi B instead of Taxi A?

So, I have a question if anyone can answer soon.

The question: Jill jumped 6 1/3 feet in the long jump. Jill’s best friend jump 6 5/7 feet. How much farther did Jill’s best friend jump?

Now I know the answer is 8/21 but every-time I look up the decimal it’s like 0.3823. But, the next question that talked about if she jumped more than 6.5 feet then the seventh graders get fifty points. Now, I have tried to look up the answer cause I though I was missing something and it all has said the best friend jumped more than 6.5. How? If the decimal was like 0.3823.

Olivia is a stockbroker. She earns 4% commission when she sells stocks. Last week, she earned 7200 in commission. a. What was the total amount of her sales?

Please help me with this??

PLEASE can anyone help me with this problem??