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3 years ago

Can some one pls help me

Mathematics

1 answer:

DedPeter [7]3 years ago

6 0

Answer:

look at the picture i have sent

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

daser333 [38]

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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3 years ago

In a fish tank, there are 24 goldfish, 2 angel fish, and 5 guppies. if a fish is selected at random, find the probability that i

Artist 52 [7]

There are a total of 31 fish in the tank. Therefore, the probability of it being a goldfish is 24/31 or about 77.4%, since there are 24 goldfish. The probability of it being an angel fish is 2/31 or about 6.45%, for the same reason as before.

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3 years ago

The local craft fair charges the vendors a flat rate of $20 plus $5 for each hour that they spend at the fair. If the vendor owe

Nonamiya [84]

Answer:He remained in the craft fair for 7 hours

Step-by-step explanation:

3 0

3 years ago

Ramil and Carly decided to make more baked goods for the bake sale. They used 1/7 lb less flour to make bread than to make cooki

STALIN [3.7K]

Lila uses lb of flour to make the bread.
Since she uses lb less to make bread than cookies then flour used to make the cookies = -
=
= lb
She used lb more flour to make cookies than brownies then flour used to make brownies = -
= = lb
Therefore, flour used to make brownies in lb.

7 0

3 years ago

A tank initially contains 40 ounces of salt mixed in 100 gallons of water. a solution containing 4 oz of salt per gallon is then

stellarik [79]

Let $A(t)$ be the amount of salt in the tank at time $t$ . We're given that $A(0)=40$ . The rate at which this amount changes is given by

$A'(t)=\dfrac{5\text{ gal}}{1\text{ min}}\cdot\dfrac{4\text{ oz}}{1\text{ gal}}-\dfrac{5\text{ gal}}{1\text{ min}}\cdot\dfrac{A(t)\text{ oz}}{100+(5-5)t\text{ gal}}$

$A'(t)+\dfrac{A(t)}{20}=20$

$e^{t/20}A'(t)+e^{t/20}\dfrac{A(t)}{20}=20e^{t/20}$

$\bigg(e^{t/20}A(t)\bigg)'=20e^{t/20}$

$e^{t/20}A(t)=400e^{t/20}+C$

$A(t)=400+Ce^{-t/20}$

Since $A(0)=40$ , we get

$40=400+C\implies C=-360$

so that the amount of salt at time $t$ is

$A(t)=400-360e^{-t/20}$

After 20 minutes, the tank contains

$A(20)=400-360e^{-20/20}\approx267.56\text{ oz}$

6 0

3 years ago