Multiply. (2.5 times 10^-8) (9 times 10^-10)

A circular swimming pool has a radius of 20 feet. A fence is going to be built so that there is a 4-foot space around the entire

Law Incorporation [45]

Answer: she forgot to multiply the radius by 2 in the formula .

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

what is the equation in slope form of the line that is parallel to the given line and passes through the point (-3,1)

viktelen [127]

Answer:

D

Step-by-step explanation:

The equation of a line in point- slope form is

y - b = m(x - a)

where m is the slope and (a, b) a point on the line

Calculate the slope of the given line using the slope formula

m = (y₂ - y₁ ) / (x₂ - x₁ )

with (x₁, y₁ ) = (- 2, - 4) and (x₂, y₂ ) = (2, 2) ← 2 points on the line

m = $\frac{2+4}{2+2}$ = $\frac{6}{4}$ = $\frac{3}{2}$

Parallel lines have equal slopes and using (a, b) = (- 3, 1), then

y - 1 = $\frac{3}{2}$ (x - (- 3)), that is

y - 1 = $\frac{3}{2}$ (x + 3) ← in point- slope form

6 0

3 years ago

Really need help..... number 14:)

Soloha48 [4]

Without the actually predicted values in comparison to the real values it is only possible to give a very likely answer based on their scale:
a) is 25 million off, which sounds bad but when compared to a few billion in population it's not even 1%
b)3 billion is more than half the world population as error: very unlikely
c)154 billion, unlikely that a prediction is off by a factor of ~30
d)same as c

so a) is most likely the solution, but in theory the predictions could be arbitrarily bad (things like negative population, or extreme growths)

4 0

3 years ago

25 x 10 to the power of 6 in standard form

VARVARA [1.3K]

Answer:

24414062 14

sj rjsjstushnaayaeyn

3 0

3 years ago

A random sample of 49 lunch customers was taken at a restaurant. The average amount of time the customers in the sample stayed i

Hunter-Best [27]

Answer:

a) σ/√n= 1.43 min

c) Margin of error 2.8028min

d) [30.1972; 35.8028]min

e) n=62 customers

Step-by-step explanation:

Hello!

The variable of interest is

X: Time a customer stays at a restaurant. (min)

A sample of 49 lunch customers was taken at a restaurant obtaining

X[bar]= 33 mi

The population standard deviation is known to be δ= 10min

a) and b)

There is no information about the distribution of the population, but we know that if the sample is large enough, n≥30, we can apply the central limit theorem and approximate the distribution of the sample mean to normal:

X[bar]≈N(μ;σ²/n)

Where μ is the population mean and σ²/n is the population variance of the sampling distribution.

The standard deviation of the mean is the square root of its variance:

√(σ²/n)= σ/√n= 10/√49= 10/7= 1.428≅ 1.43min

c)

The CI for the population mean has the general structure "Point estimator" ± "Margin of error"

Considering that we approximated the sampling distribution to normal and the standard deviation is known, the statistic to use to estimate the population mean is Z= (X[bar]-μ)/(σ/√n)≈N(0;1)

The formula for the interval is:

[X[bar]± $Z_{1-\alpha /2}$ *(σ/√n)]

The margin of error of the 95% interval is:

$Z_{1-\alpha /2}= Z_{1-0.025}= Z_{0.975}= 1.96$

d= $Z_{1-\alpha /2}$ *(σ/√n)= 1.96* 1.43= 2.8028

d)

[X[bar]± $Z_{1-\alpha /2}$ *(σ/√n)]

[33±2.8028]

[30.1972; 35.8028]min

Using a confidence level of 95% you'd expect that the interval [30.1972; 35.8028]min contains the true average of time the customers spend at the restaurant.

e)

Considering the margin of error d=2.5min and the confidence level 95% you have to calculate the corresponding sample size to estimate the population mean. To do so you have to clear the value of n from the expression:

d= $Z_{1-\alpha /2}$ *(σ/√n)

$\frac{d}{Z_{1-\alpha /2}}$ = σ/√n

√n*( $\frac{d}{Z_{1-\alpha /2}}$ )= σ

√n= σ* ( $\frac{Z_{1-\alpha /2}}{d}$ )

n=( σ* ( $\frac{Z_{1-\alpha /2}}{d}$ ))²

n= (10* $\frac{1.96}{2.5}$ )²= 61.47≅ 62 customers

I hope this helps!

3 0

2 years ago