For each problem, select the best response.
1. Does 30 minutes of aerobic exercise each day provide significant improvement in mental performance? To investigate this issue, a researcher conducted a study with 150 adult subjects who performed aerobic exercise each day for a period of six months. At the end of the study, 200 variables related to the mental performance of the subjects were measured on each subject and the means compared to known means for these variables in the population of all adults. Nine of these variables were significantly better (in the sense of statistical significance) at the ???? = 0.05 level for the group that performed 30 minutes of aerobic exercise each day as compared to the population as a whole, and one variable was significantly better at the ???? = 0.01 level for the group that performed 30 minutes of aerobic exercise each day as compared to the population as a whole. It would be correct to conclude:_____.
a. that these results would have provided very good statistical evidence that 30 minutes of aerobic exercise each day provides some improvement in mental performance if the number of subjects had been larger. It is pre-mature to draw statistical conclusions from studies in which the number of subjects is less than the number of variables measured.
b. that there is very good statistical evidence that 30 minutes of aerobic exercise each day provides some improvement in mental performance.
c. that there is very good statistical evidence that 30 minutes of aerobic exercise each day provides improvement for the variable that was significant at the α = 0.01 level. We should be somewhat cautious about making claims for the variables that were significant at the α = 0.05 level.
d. none of the above.
2. The nicotine content in cigarettes of a certain brand is normally distributed with mean (in milligrams) μμ and standard deviation σ = 0.1. The brand advertises that the mean nicotine content of their cigarettes is 1.5, but you believe that the mean nicotine content is actually higher than advertised. To explore this, you test the hypotheses H0 : μ = 1.5, Ha : μ > 1.5 and you obtain a P-value of 0.052. Which of the following is true?
A. There is some evidence against H0, and a study using a larger sample size may be worthwhile.
B. You have failed to obtain any evidence for Ha.
C. This should be viewed as a pilot study and the data suggests that further investigation of the hypotheses will not be fruitful at the α = 0.05 significance level.
D. At the α = 0.05 significance level, you have proven that H0 is true.
3. An engineer designs an improved light bulb. The previous design had an average lifetime of 1200 hours. The new bulb had a lifetime of 1200.2 hours, using a sample of 40,000 bulbs. Although the difference is quite small, the effect was statistically significant. The explanation is:____.
a. that the sample size is very large.
b. that the mean of 1200 is large.
c. that new designs typically have more variability than standard designs.
d. all of the above.
Answer:
1. d. none of the above.
2. A. There is some evidence against H0, and a study using a larger sample size may be worthwhile.
3.a. that the sample size is very large.
Step-by-step explanation:
1. This experimental analysis is incomplete so none of the options provides the best solution. Therefore the correct answer is choice D.
2. The smallest value which provides basis for rejection for H0 at ∝= 0.05 is P= 0.05.
As P= 0.052 but we are not sure about other variables such as sample size. So option A is the best choice
A. There is some evidence against H0, and a study using a larger sample size may be worthwhile.
3. A sample of 40,000 bulbs will provide a wider range for the results. Therefore the sample size is too large to accurately predict the results .
Hence choice a gives the best answer that the sample size is too large.
There are 9,481 eligible voters in a precinct. 500 were selected at random and asked to indicate whether they planned to vote for the Democratic incumbent or the Republican challenger. Of the 500 surveyed, 350 said they were going to vote for the Democratic incumbent. Using an 80% confidence level, what are the confidence limits for the proportion that plan to vote for the Democratic incumbent
Answer:
The confidence limits for the proportion that plan to vote for the Democratic incumbent are 0.725 and 0.775.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
Of the 500 surveyed, 350 said they were going to vote for the Democratic incumbent.
This means that [tex]n = 500, \pi = \frac{350}{500} = 0.75[/tex]
80% confidence level
So [tex]\alpha = 0.2[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.2}{2} = 0.9[/tex], so [tex]Z = 1.28[/tex].
The lower limit of this interval is:
[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.75 - 1.28\sqrt{\frac{0.75*0.25}{500}} = 0.725[/tex]
The upper limit of this interval is:
[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.75 + 1.28\sqrt{\frac{0.75*0.25}{500}} = 0.775[/tex]
The confidence limits for the proportion that plan to vote for the Democratic incumbent are 0.725 and 0.775.
The penguin exhibit at a zoo has a raised circular island that is surrounded by water. The diameter of the island is 20 \text{ meters}20 meters20, start text, space, m, e, t, e, r, s, end text. One penguin swims half way around the island before hopping out.
How far did the penguin swim?
Give your answer in terms of pi.
Answer:
31.42 m
Step-by-step explanation:
Since, the path is circular :
The distance traveled can be I tin by taking the Circumference of the path :
Circumference, C = πd
d = diameter = 20 meters
C = π * 20
Since penguin swam. Only halfway around the island.
Hence, distance traveled = 1/2 * C
= 1/2 * 20π
= 31.42 m
Lorenzo's Survey Results
Food Number of Students
Pizza
8
Hamburger
12
Pasta
14
Steak
6
Lorenzo recorded the favorite food of
students in his class. According to the
results of the survey, what percent of the
students chose Hamburger?
Answer:
30%
Step-by-step explanation:
First, add all of the numbers together and you get 40. After, you divide 12 by 40 and you get 0.3. Next, you have to multiply that by 100 and you get 30%.
Hello, here with geometry questions!
Please only answer if you know the answer, the comment section is right below. Please don't waste my points!
Also, please show all of your work, you are trying to help me better understand the concept, not just give me the answer.
The image is down below. Show work! Thanks!
Answer:
5/12
Step-by-step explanation:
tanZ = XY/YZ = 15/36 = 5/12
Question 4
1
Justin regularly eats in the Cafeteria at work. On Monday
Justin bought 2 hamburgers and 1 carton of milk for $2.85.
On Tuesday Justin purchased 3 hamburgers and 2 cartons of
milk for $4.45. How much does a carton of milk cost?
a. $0.35
b. $0.50
c. $0.75
d. $0.85
3. Use congruent triangles to find side lengths.
Part I: Draw the two congruent triangles described in the box. Label their vertices and side lengths.
(2 points)
AABC AEFG
AB = 6, GF = 8, AC = 10.
The value on the congruent triangles are BC = 8, EF = 6, and EG = 10.
How to illustrate the graph?It should be noted that a triangle is congruent if they have the same length and the same angles
In this case, triangles ABC and EFG are congruent.
Here, BC = 8
EF = 6
EG = 10
Learn more about triangles on:
brainly.com/question/1058720
#SPJ1
-12(5/6a-7/8)+1/14(3 1/2-1 2/5)
Answer:
10a + 10.65
Step-by-step explanation:
- 12(5/6a - 7/8) + 1/14(3.5 - 1.4)
- 12(5/6a - 7/8) + 0.25 - 0.1
10a + 10.5 + 0.25 - 0.1
10a + 10.65
What acceleration will result when a 12 N force is applied to a 6 kg object?
If you know please include the equation, it would really help me out, thanks so much!
Hi there!
[tex]\large\boxed{2 m/s^{2}}[/tex]
Use the equation F = m · a where:
F = Force (N)
m = mass (kg)
a = acceleration (m/s²)
Plug in the given values:
12 = 6a
Divide both sides by 6:
12/6 = a
a = 2 m/s²
The Spanish club collected $13.45 from each of its nine members. How
much did the Spanish club collect?
Answer:
$121.05
Step-by-step explanation:
Answer:
$121.05
Step-by-step explanation:
Since we are told that there is 9 members and each once is 13.45 we can simply do 13.45 times 9 to get the number 121.05.
A cleaning company's monthly earnings depend on the
number of houses cleaned, h. Spotless Homes charges
$150 each month to clean one house.
The owners of Spotless Homes plan to raise their fees
starting next month. They will charge $175 each month to
clean each house. The owners write this new equation to
represent the new earnings, e, for cleaning h houses:
e = 150 + 25h
Is their equation correct? Why or Why not? Explain your
reasoning
Answer:
The equation is not correct because the statement indicates that they charged $150 to clean one house which means that the equation showed that the earnings were the result of multiplying the price to clean one house for the number of houses cleaned, which is:
e=150h
As the statement indicates that they plan to raise their fees and they will charge $175 to clean each house, this means that the price changes from 150 to 175 and you have to replace this in the formula and because of this the new equation would be:
e=175h
The equation the owners wrote is not right because it shows that the earnings are equal to a fixed charge of $150 plus a price of $25 for the number of houses and the statement says that the price is $175 for each house so the number of houses cleaned should be multiplied for that price.
HElP ME 5th grade math
Answer:
(4.80 x 0.05) + 4.80
Step-by-step explanation:
What TWO steps do you take to solve the following equation: 5x - 3 = 12
Answer:
First add 3 to each side
Then divide each side by 5
Step-by-step explanation:
5x - 3 = 12
First add 3 to each side
5x-3+3 = 12+3
5x = 15
Then divide each side by 5
5x/5 = 15/5
x = 3
Answer:
3
Step-by-step explanation:
5x = 12 + 3
x = 15/5
x = 3
What is the minimum value of h(x)?
h(x) = (x - 5)^2 + 6
Answer:
see in pdf the solution is there.
Step-by-step explanation:
The question is in this link (please fast):
Answer:
a) 190
b)-189
Step-by-step explanation:
4a)
-2y+7(4+8y)=
-2y+(7·4)+(7·8y)=
-2y+28+(7·8y)=
-2y+28+(7·24)
-2y+28+168=
-6+28+168=
22+168 solve
4b)
-5w-4(6t+5)
-5w-4(36+5)
-5w-(4·41)
-5w-164
-25-164 solve
HELP I HAVE A TEST TOMORROW!!! Two of the angles in a triangle measure 19° and 83°. What is the measure of the third angle?
Answer:
78
Step-by-step explanation:
19 + 83+ x = 180
102 + x = 180 - 102
x= 78
Does the relation in the table represent direct variation, inverse variation, or neither? If it is director
inverse variation, write an equation to represent the relation. Explain your answer.
9514 1404 393
Answer:
inverse
y = 10/x
Step-by-step explanation:
Inverse variation is described by an equation of the form ...
y = k/x
The value of k is a constant equal to ...
k = xy = 5·2 = 10·1 = 15·2/3 = 20·1/2 = 10
__
Here, the products of the x- and y-values are all 10, so the inverse variation equation is ...
y = 10/x
-14 is less than or equal to x.
Question options:
-14 > x
-14 ≥ x
-14 ≤ x
-14 < x
Answer:
C
Step-by-step explanation:
This sign "≤" has both the less sign and the equal sign so it indicates that -14 is less than or equal to x.
solve (x+5)/3 = 4 for x
please help asap
Answer:
x=7, because 7 plus 5 is 12 and 12 divided by 3 is 4
Step-by-step explanation:
7+5=12/3=4
For the following studies in which tests comparing two means are conducted, select whether the populations are independent or matched pairs:
a. A study is conducted to see what effect a new drug has on dexterity. A random sample of 30 people is chosen. They are given a series of tasks to perform and a score reflecting their performance. A dose of the drug is administered to the 30 people, and they are then given a similar series of tasks to perform and scored again.
b. A study is conducted to determine the difference between the average amount that people spend on durables and non-durables when they go shopping. A sample of people is chosen and their shopping purchases are observed.
c. A study is conducted to determine if there is a difference between the average length of time spent in traffic on the way to work and the average length of time spent in traffic going home from work for people in a city. A random sample of workers is chosen and asked how long they spend getting to work. Another separate random sample of workers is chosen and asked how long they spend getting home from work.
Answer:
a. Independent
b. Matched
c. Independent
Step-by-step explanation:
If the sample is chosen randomly and there is no biasness in the selection of sample from the population then the selected sample is independent. The matched pairs are when the selection process involves a relation with the sample selected with the desired test results.
We can conclude that:
a. the population is independent.
b. the population is matched.
c. the population is independent.
What are Independent and Matched Populations?If a researcher selects a sample from an entire population under study in a random and unbiased manner, the sample population is aid to be independent.
If the selection process in drawing the sample involves a relation with what is expected from the test results, then they are is matched pairs.
Thus, we can conclude that:
a. the population is independent.
b. the population is matched.
c. the population is independent.
Learn more about independent and matched populations on:
https://brainly.com/question/17143411
Answer!asap if you are a bot don't even respond
Answer:
Step-by-step explanation:
Upon factoring all terms we are left with the product of
[(x-4)(x+6)(x-6)]/[5(x-6)(3x+5)(x-4)]
The (x-4)s and (x-6)s cancel out and we are left with
(x+6)/(5(3x+5)) which is also equal to
(x+6)/(15x+25)
What is the distance between -2 1/2, 4 1/2 and 4 3/4, 4 1/2
A. 2 1/4 units
B. 4 1/2 units
C. 7 1/4 units
D. 9 1/4 units
Please help this is due tomorrow :(
9514 1404 393
Answer:
C. 7 1/4 units
Step-by-step explanation:
It can be useful to plot the points on a graph.
The two points are on the same horizontal line, so the distance between them is the difference of their x-coordinates.
4 3/4 -(-2 2/4) = (6 +2) +(3/4 +2/4) = 6 5/4 = 7 1/4 . . . . units
__
Some folks find it easier to do the arithmetic by converting to decimal numbers.
4.75 -(-2.50) = 4.75 +2.50 = 7.25 = 7 1/4 . . . . units
Find the volume for the regular pyramid
A) 6 cu. units B)12 cu. units C)4 cu. units
Answer:
i found the volume it next to the power button on my keyboard
Step-by-step explanation:
find the value of the expression below for x = 10
x'2 - 2(x+5)
A:10
B:70
C:85
D:90
Please answer quick and just write explanation quick pls hurry quick for brainlessly
Answer: B
Step-by-step explanation: Thats the same thing i got but ik the answer its:
Answer:
A) (x+3)(x-2)
Step-by-step explanation:
If you factor correctly, you would get this answer. You can also try to unfactor all the answer choices to get the answer as well.
Paul owns a gym and needs to replace the carpeting on the floor. The gym's floor plan is shown.
8 yd
3 yd
4 yd
المة
How many square yards of carpeting is needed to cover the entire gym?
O 18 square yards
O 24 square yards
O 36 square yards
44 square yards
Answer:
24 square yards
Step-by-step explanation:
Find the diagram attached.
The area of the diagram = Area of rectangle + Area of triangle
Area of rectangle = 3 * 4
Area of rectangle = 12 square yards
Area of triangle = 1/2 * base * height
Area of triangle = 1/2 * 6 * 4
Area of triangle = 12 square yards
Area of the diagram = 12 + 12
Area of diagram = 24 square yards
Hence 24 square yards of carpeting is needed
Which graph represents the solution set for the inequality: y > x-1
Answer:
F
Step-by-step explanation:
How many square feet of outdoor carpet will
we need for this hole?
Answer:
This is your answer ☺️☺️☺️
Help me i need to pass this class?
Answer:
3: 58 (72-14=58)
4. 182 (91x2=182. two negatives equal a positive so thats why it has to be 182 and not -182)
5. 6 (3x6=18)
7. -2 (-6x-2=12 12-3 =9)
8.-3 (4x-3= -12 -2 = -14)
11. 3 (2x3=6 +5=11) 6(11)=66
How many cubic centimeters will it take to fill the prism below?
960
1920
ООО
48
240
Answer:
there is no picture here! sorry wish I could help more