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sammy [17]
2 years ago
13

Automobile engineers wanted to check the effect of a new automatic transmission on mileage. They selected 50 cars of the same ma

ke and model. Twenty-five of the cars used the old transmission, while the other 25 cars used the new model of transmission. A hypothesis test on the difference between the means was conducted. Which one of the following is a condition necessary to conduct this test?
a. The standard deviation of each group should be different.
b. The sampling distribution of the difference between the sample means is bimodal.
c. Since the data were random, no linear regression was possible.
d. Twenty-five cars are randomly selected with the new transmission and 25 with the old transmission.
e. The difference between the means was within one standard deviation.
Mathematics
1 answer:
daser333 [38]2 years ago
3 0

Answer:

d. Twenty-five cars are randomly selected with the new transmission and 25 with the old transmission.

Step-by-step explanation:

A hypothesis test on the difference between the means must satisfy the following conditions

1) the samples must be randomly selected

2) each sample must have a known standard deviation

3) the samples must be independent

4) the samples must be from normal distribution

Hence only part d gives the right answer.

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Find the area of the shaded region in square units ​
Kaylis [27]

Answer:

There is nothing there...

Step-by-step explanation:

I wish I could help you but you need to put in a picture or diagram

5 0
2 years ago
Mae Ling earns a weekly salary of $310 plus a 6.5% commission on sales at a gift shop. How much would
Kryger [21]

Answer:

$325

Step-by-step explanation:

Mae Ling earns a weekly salary of $325 plus a 6.5% commission on sales at a gift shop. How much would she make in a work week if she sold $4,800 worth of merchandise?

7 0
2 years ago
Read 2 more answers
ANSWER PLEASE Tyler deposits $2000 and has a 8% interest compound quarterly. How much does he have Quarter 1,2,3,4 Show Work
guajiro [1.7K]

Answer:

If the time passed is only 3 months, then it is $2040

Step-by-step explanation:

We can use the quarterly compounded interest equation for this problem: P(1 + r/n)^nt

Step 1: Find out how much 3 months is in a year

<em>In this case, 3/12 which is 1/4</em>

Step 2: Plug in known variables into equation

2000[1 + (0.08)/4)]^[(4)(1/4)]

Step 3: Solve/Plug in calc

You will get $2040

If the time passed in the problem is 1 year, then we can be able to solve how much money he earned per quarter. However, since only 3 months have elapsed, then he has only earned $2040.

7 0
3 years ago
Find the 2th term of the expansion of (a-b)^4.​
vladimir1956 [14]

The second term of the expansion is -4a^3b.

Solution:

Given expression:

(a-b)^4

To find the second term of the expansion.

(a-b)^4

Using Binomial theorem,

(a+b)^{n}=\sum_{i=0}^{n}\left(\begin{array}{l}n \\i\end{array}\right) a^{(n-i)} b^{i}

Here, a = a and b = –b

$(a-b)^4=\sum_{i=0}^{4}\left(\begin{array}{l}4 \\i\end{array}\right) a^{(4-i)}(-b)^{i}

Substitute i = 0, we get

$\frac{4 !}{0 !(4-0) !} a^{4}(-b)^{0}=1 \cdot \frac{4 !}{0 !(4-0) !} a^{4}=a^4

Substitute i = 1, we get

$\frac{4 !}{1 !(4-1) !} a^{3}(-b)^{1}=\frac{4 !}{3!} a^{3}(-b)=-4 a^{3} b

Substitute i = 2, we get

$\frac{4 !}{2 !(4-2) !} a^{2}(-b)^{2}=\frac{12}{2 !} a^{2}(-b)^{2}=6 a^{2} b^{2}

Substitute i = 3, we get

$\frac{4 !}{3 !(4-3) !} a^{1}(-b)^{3}=\frac{4}{1 !} a(-b)^{3}=-4 a b^{3}

Substitute i = 4, we get

$\frac{4 !}{4 !(4-4) !} a^{0}(-b)^{4}=1 \cdot \frac{(-b)^{4}}{(4-4) !}=b^{4}

Therefore,

$(a-b)^4=\sum_{i=0}^{4}\left(\begin{array}{l}4 \\i\end{array}\right) a^{(4-i)}(-b)^{i}

=\frac{4 !}{0 !(4-0) !} a^{4}(-b)^{0}+\frac{4 !}{1 !(4-1) !} a^{3}(-b)^{1}+\frac{4 !}{2 !(4-2) !} a^{2}(-b)^{2}+\frac{4 !}{3 !(4-3) !} a^{1}(-b)^{3}+\frac{4 !}{4 !(4-4) !} a^{0}(-b)^{4}=a^{4}-4 a^{3} b+6 a^{2} b^{2}-4 a b^{3}+b^{4}

Hence the second term of the expansion is -4a^3b.

3 0
3 years ago
Bob sells part of a 50-acre rectangular plot of land he owns so that he can still own a smaller rectangular plot within the orig
Nuetrik [128]

Considering the area of a rectangle, it is found that the area of Bob's remaining plot of land is of 12.5 acres.

<h3>What is the area of a rectangle?</h3>

The area of a rectangle of length l and width w is given by the multiplication of these dimensions, that is:
A = lw.

In this problem, both the length and the width are divided in half, hence the proportion remaining is given by:

A = 0.5l x 0.5w = 0.25lw = 25% of the initial area.

Hence:

0.25 x 50 = 12.5.

The area of Bob's remaining plot of land is of 12.5 acres.

More can be learned about the area of a rectangle at brainly.com/question/10489198

#SPJ1

5 0
1 year ago
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