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2 years ago

A chemist mixes different concentrations of

Mathematics

2 answers:

maks197457 [2]2 years ago

7 0

Answer:

10 oz

Step-by-step explanation:

I got it right on E

Aneli [31]2 years ago

7 0

Answer:

10 oz

Step-by-step explanation:

edge

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Which equation below shows a correct first step for solving 3x = -12

Wewaii [24]

The answer is A. You just solve each one and you would find that it would be the same as 3x=-12.

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1 year ago

A boy climbs to the top of a tree and sees his friend 100 feet from the base of the tree. If the tree is 25 feet tall, what is t

QveST [7]

It would be helpful to draw the figure for this system. We would see that a right triangle is made where the base is equal to 100 ft and the height is equal to 25 ft. Using trigonometric functions we can easily calculate for the angle as follows:

tan (theta) = 25 / 100
theta = 14.04 degrees

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2 years ago

While remodeling her kitchen Angela is repainting. She estimates that she paints 55 square feet every half-hour. How many square

madreJ [45]

110 square feet. 55x2=100

5 0

1 year ago

According to a Pew Research survey, about 27% of American adults are pessimistic about the future of marriage and the family. Th

IgorLugansk [536]

Answer:

P(X≤5)=0.5357

Step-by-step explanation:

Using the binomial model, the probability that x adults from the sample, are pessimistic about the future is calculated as:

$P(x)=\frac{n!}{x!(n-x)!} *p^{x}*(1-p)^{n-x}$

Where n is the size of the sample and p is the probability that an adult is pessimistic about the future of marriage and family. So, replacing n by 20 and p by 0.27, we get:

$P(x)=\frac{20!}{x!(20-x)!}*0.27^{x}*(1-0.27)^{20-x}$

Now, 25% of 20 people is equal to 5 people, so the probability that, in a sample of 20 American adults, 25% or fewer of the people are pessimistic about the future of marriage and family is equal to calculated the probability that in the sample of 20 adults, 5 people of fewer are pessimistic about the future of marriage and family.

Then, that probability is calculated as:

P(X≤5)= P(1) + P(2) + P(3) + P(4) + P(5)

Where:

$P(0)=\frac{20!}{0!(20-0)!}*0.27^{0}*(1-0.27)^{20-0}=0.0018$

$P(1)=\frac{20!}{1!(20-1)!}*0.27^{1}*(1-0.27)^{20-1}=0.0137$

$P(2)=\frac{20!}{2!(20-2)!}*0.27^{2}*(1-0.27)^{20-2}=0.0480\\P(3)=\frac{20!}{3!(20-3)!}*0.27^{3}*(1-0.27)^{20-3}=0.1065\\P(4)=\frac{20!}{4!(20-4)!}*0.27^{4}*(1-0.27)^{20-4}=0.1675\\P(5)=\frac{20!}{5!(20-5)!}*0.27^{5}*(1-0.27)^{20-5}=0.1982$

Finally, P(X≤5) is equal to:

P(X≤5) = 0.0018+0.0137 + 0.0480 + 0.1065 + 0.1675 + 0.1982

P(X≤5) = 0.5357

3 0

2 years ago

One of your employees has suggested that your company develop a new product. You decide to take a random sample of your customer

iren [92.7K]

Answer:

269

Step-by-step explanation:

The margin of Error is E = 0.05

The level of significance is, α = 1 - confidence level = 1 - 0.9 = 0.1

Assume that the proportion is, p =0.5

From the standard normal table, observe that the critical value of Z for two tail test and 10% level of significance is 1.64

The calculation of sample size is as follows: n = (Z/E)²p(1-p)

n = (1.64/0.05)²0.5 (1 - 0.5)

n = (1.64/0.05)² 0.25

n = 1075.84 × 0.25

n = 268.96 ≈ 269

The required sample size with the given margin of error approximately is 269. This value indicates the size of the customers who are using this company’s products.

6 0

2 years ago