Double the second number, the sum is 34."

Andrej [43]

Answer:

2.87

Step-by-step explanation:

2.868

6 is in the hundredths place

To round, look to the right of the number rounding up, if number is higher than 5, round up if its lower than 4, the number will remain the same.

4 0

2 years ago

A geologist examines 6 seawater samples for lead concentration. The mean lead concentration for the sample data is 0.903 cc/cubi

Gnesinka [82]

Answer:

Step-by-step explanation:

We want to determine a 95% confidence interval for the mean lead concentration of sea water samples

Number of samples. n = 6

Mean, u = 0.903 cc/cubic meter

Standard deviation, s = 0.0566

For a confidence level of 95%, the corresponding z value is 1.96. This is determined from the normal distribution table.

We will apply the formula

Confidence interval

= mean +/- z ×standard deviation/√n

It becomes

0.903 +/- 1.96 × 0.0566/√6

= 0.903 +/- 1.96 × 0.0566/2.44948974278

= 0.903 +/- 0.045

The lower end of the confidence interval is 0.903 - 0.045 =0.858

The upper end of the confidence interval is 0.903 + 0.045 =0.948

Therefore, with 95% confidence interval, the mean lead concentration of the sea water is between 0.858 cc/cubic meter and 0.948 cc/cubic meter

7 0

3 years ago

Sasha can mow 3/8 of an acre of grass in 45minutes.how many acres of grass does Sasha now per hour?

horrorfan [7]

Keeping in mind that an hour is 60 minutes.

$\bf \begin{array}{ccll}
\stackrel{acre}{grass}&\stackrel{minutes}{time}\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
\frac{3}{8}&45\\
g&60
\end{array}\implies \cfrac{\frac{3}{8}}{g}=\cfrac{45}{60}\implies \cfrac{\frac{3}{8}}{\frac{g}{1}}=\cfrac{45}{60}\implies \cfrac{3}{8}\cdot \cfrac{1}{g}=\cfrac{45}{60}
\\\\\\
\cfrac{3}{8g}=\cfrac{45}{60}\implies 180=360g\implies \cfrac{180}{360}=g\implies \cfrac{1}{2}=g$

6 0

3 years ago

There were 165 donors last year. Find the number of donors this year using each of the expressions. Do you get the same number w

pochemuha

Answer:

We need to see the expressions given

Step-by-step explanation:

4 0

3 years ago

Let f(x) = log(x). Find values of a such that f(kaa) = kf(a).

meriva

Answer:

a = $k^{\frac{1}{k-2}}$

Step-by-step explanation:

Given:

f(x) = log(x)

and,

f(kaa) = kf(a)

now applying the given function, we get

⇒ log(kaa) = k × log(a)

or

⇒ log(ka²) = k × log(a)

Now, we know the property of the log function that

log(AB) = log(A) + log(B)

and,

log(Aᵇ) = b × log(A)

Thus,

⇒ log(k) + log(a²) = k × log(a) (using log(AB) = log(A) + log(B) )

or

⇒ log(k) + 2log(a) = k × log(a) (using log(Aᵇ) = b × log(A) )

or

⇒ k × log(a) - 2log(a) = log(k)

or

⇒ log(a) × (k - 2) = log(k)

or

⇒ log(a) = (k - 2)⁻¹ × log(k)

or

⇒ log(a) = $\log(k^{\frac{1}{k-2}})$ (using log(Aᵇ) = b × log(A) )

taking anti-log both sides

⇒ a = $k^{\frac{1}{k-2}}$

3 0

3 years ago