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2 years ago

How much alfalfa does Helmut need to add to 30L of ostrich pellets to make a feed mix that is 40% alfalfa by volume?

Mathematics

1 answer:

Nutka1998 [239]2 years ago

8 0

Answer:

a = 20 . . . . liters

Step-by-step explanation:

To solve this, multiply the equation by 30+a:

a = 0.4(30 +a)

a = 12 + 0.4a . . . . . eliminate parentheses

0.6a = 12 . . . . . . . . subtract 0.4a

a = 12/0.6 = 20 . . . divide by the coefficient of a

20 L of alfalfa must be added

_____

Check

20/(30+20) = 20/50 = 40/100 = 0.4 . . . . . . answer checks OK

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g An irate student complained that the cost of textbooks was too high. He randomly surveyed 36 other students and found that the

blagie [28]

Answer:

A 90% confidence interval of the true mean is [$119.86, $123.34].

Step-by-step explanation:

We are given that an irate student complained that the cost of textbooks was too high. He randomly surveyed 36 other students and found that the mean amount of money spent on textbooks was $121.60.

Also, the standard deviation of the population was $6.36.

Firstly, the pivotal quantity for finding the confidence interval for the population mean is given by;

P.Q. = $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\bar X$ = sample mean amount of money spent on textbooks = $121.60

$\sigma$ = population standard deviation = $6.36

n = sample of students = 36

$\mu$ = population mean

Here for constructing a 90% confidence interval we have used One-sample z-test statistics as we know about population standard deviation.

So, 95% confidence interval for the population mean, $\mu$ is ;

P(-1.645 < N(0,1) < 1.645) = 0.90 {As the critical value of z at 5% level

of significance are -1.645 & 1.645}

P(-1.645 < $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ < 1.645) = 0.90

P( $-1.645 \times {\frac{\sigma}{\sqrt{n} } }$ < ${\bar X-\mu}$ < $1.645 \times {\frac{\sigma}{\sqrt{n} } }$ ) = 0.90

P( $\bar X-1.645 \times {\frac{\sigma}{\sqrt{n} } }$ < $\mu$ < $\bar X+1.645 \times {\frac{\sigma}{\sqrt{n} } }$ ) = 0.90

90% confidence interval for $\mu$ = [ $\bar X-1.645 \times {\frac{\sigma}{\sqrt{n} } }$ , $\bar X+1.645 \times {\frac{\sigma}{\sqrt{n} } }$ ]

= [ $121.60-1.645 \times {\frac{6.36}{\sqrt{36} } }$ , $121.60+1.645 \times {\frac{6.36}{\sqrt{36} } }$ ]

= [$119.86, $123.34]

Therefore, a 90% confidence interval of the true mean is [$119.86, $123.34].

5 0

2 years ago

what is the value of the constant in the equation that relates the height and width of this rectangle

Doss [256]

The correct answer is C. 1.5

You can find this answer by using any of the points on the graph and putting them into the given equation. Then you can solve for the constant. For the purpose of this example, we will use (10, 15)

Height = Constant * Width ---> Plug in known values.

15 = Constant * 10 ----> Divide both sides by 10

1.5 = Constant

This will work with whatever numbers you use from the graph. Although this graph does not have any others to really choose from.

8 0

1 year ago

An iPhone costs £699 in London, €799 in Paris and $1,099 in New York. Using £1 = €1.13 and £1 = $1.37, state the lowest price of

Alex787 [66]

Answer:

£699 in London

£902.87 in Paris

£1505.63 in New York

The lowest price of the iPhone is £699 in London.

3 0

1 year ago

The populations and areas of four states are shown. A 3-column table has 4 rows. The first column has entries State A, State B,

dedylja [7]

Answer:

Step-by-step explanation:

First, pop. density for State A:

population/area : 1,055,173 / 2,677 = 394.16

For State B:

pop./A : 1,333,089 / 36,418 = 36.61

For State C:

pop.A : 3,596,677 / 5,543 = 648.87

For State D:

pop./A : 6,745,408 / 10,555 = 639.07

Okay!

So with this data, we can easily rule out the first option (State A has the least population, but it isn't the most densely populated). Moving on to the second option, we see that the state with the second-lowest population, State B, also has the lowest population density! Thus, our answer is B (haha which is coincidentally the State name).

6 0

2 years ago

Read 2 more answers

You want to rent a television Company A charges $25 per week plus a one-time fee of $52. Company B charges $37 per week plus a o

pickupchik [31]

Answer: They will be the same after 3 weeks $127

Step-by-step explanation:

4 0

2 years ago