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.

You have four ice cubes in your cup of lemonade each ice cube has a length of 2 1/4 cm a width of 2 2/3 cm and a height of 2 cm what is the total volume of all the ice cubes

If the circumference of a circle measures 3/2TT cm, what is the area of the circle in terms of TT?
A. 3/4 tt cm2
B. 9/2 tt cm2
C. 9/4 tt cm2
D. 9/16 tt cm2

Jared bakes 2 apple pies he cuts the 2 pies into pieces each pieces is 1\8 of a pie​

In 2020, you purchase a car for $8000. The value of the car depreciates by 4% each year. What will the approximate value of the car be in 2027? *

A number decreased by 90 is 22.

0.2 as a fraction (out of 100)

IF YOU ARE GOOD AT MATH I NEED YOUR HELP REALLY BAD ATM . THIS CAN ALSO HAVE MORE THAN 1 ANSWER :)

Find the slope of the line that passes through (1, 11) and (9, 10).

Simplify your answer and write it as a proper fraction, improper fraction, or integer.

Can someone help me? =)

What is 54.77 rounded to the nearest hundredth ?

Tennis practice last for 1 hour and 35 minutes

What is the value of the expression
401P + q?), when p = 49 and q = -2?
O A) 12
OB) 20
OC) 36
OD) 44

First person to answer will get 10 points :D

Spaulding is the leading maker for basketballs in the US. Spaulding prides itself on the quality that its basketballs have the right amount of bounce when it is taken out of the packaging. They want their product to be ready for use upon opening. The air pressure of a particular ball has a target value of 7.9 PSI. Suppose the basketballs have a normal distribution with a standard deviation of 0.20 PSI. When a shipment of basketballs arrive, the consumer takes a sample of 21 from the shipment and measures their PSI to see if it meets the target value, and finds the mean to be 7.3 PSI. Perform this hypothesis test at the 5% significance level using the critical value approach.

Find anequation of the line containing (3,-4) and having slope -2. If this line
contains the points (2,8) and (5.b), find a and b.​

PLEEEEASSEEEEE ITS URGENT
I NEED THE ANSWER RIGHT NOW!!!!
I BEEEG YOU GUUYYS!!!
PLEEEASEE ....
THANKS FOR THE HELP​

Approximately 32800 citizens of a country died in automobile accidents in 2015

what fraction is bigger? 7/10, 1/5, 9/10
​

The table below shows the different sizes of 15 pepperoni pizzas sold at a restaurant so far today.
Based on this table what is the probibilty that the next peperonni pizza prize sold will be 8 or more pieces

find the value of x ​

I need help!
Can you help me please!

please help me pleassee​

Thirty eight years ago George was 14. how old is he now

what is the value of y? ​

Four boys shared an apple. The amount each boy ate is listed below. Joey ate 1 2 of the apple. Max ate 1 8 of the apple. Chris ate 1 8 of the apple. Kevin ate 1 8 of the apple. How much of the apple did they eat altogether?

help me plz with that ​

A store sold 14 more colored shirts than white shirts. The white shirts cost $9.95 and colors cost $10.50. If a total of $310.60 were sold, how many of each type were sold?

Select the statement that describes this expression: 8 + fraction 1 over 2 x (6 − 2) − 1. (2 points)

Group of answer choices

8 more than half the difference of 2 and 1, and then subtract 6

Add 8 to half the difference of 6 and 2, then subtract 1

The sum of 8 and fraction 1 over 2 times 6 plus 2 minus 1

1 less than half of 6 plus the sum of 8 and 2

what is 1+1 please help me?

Mr. Kramer bought his daughter a kitten for her birthday, so now he needs to buy cat food. First, he gets a 20-pound bag of dry cat food. Then, he finds a good deal on 3-ounce cans of wet cat food, so he buys 48 of them. How many pounds of cat food does Mr. Kramer get in all?

the length of a rectangle is 6 feet longer than its width the perimeter is less than 48 feet write a mathematical expression for the width of the rectangle