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3 years ago

Explain how to find the constant of proportionality for the ratio of robins to cardinals.

Mathematics

1 answer:

mash [69]3 years ago

4 0

Answer:

Divide the number of robins by the number of cardinals for each pair of values. The ratios are the same and are a constant of proportionality of 3.

Step-by-step explanation: I took the test on Edgenuity.

You might be interested in

Find the surface area of regular prism with height 6 cm, if the base of the prism is: Regular quadrilateral with side 4 cm.

mafiozo [28]

A "regular quadrilateral" is a square, so the length and width are both 4 cm. The surface area of a rectangular prism is given by
S = 2(LW +H(L +W))
S = 2((4 cm)*(4 cm) +(6 cm)*(4 cm +4 cm))
S = 2(16 cm² +48 cm²)
S = 2*64 cm² = 128 cm²

The surface area of the prism is 128 cm².

5 0

3 years ago

Read 2 more answers

Help answer 1 and 2 pls

Serjik [45]

Answer:

1. 0,4

2. x=-2

Step-by-step explanation:

5 0

3 years ago

Cell phone usage differs by gender. The role of cell phone in modern life was investigated by Pew Internet and American life pro

ahrayia [7]

Answer:

A) Two populations: American men and American women, as it estimated from the broad of the survey.

B) The proportion of men that sometimes do not drive safely while talking or texting on cell phone is 32%, and the proportion of women that sometimes do not drive safely while talking or texting on cell phone is 25%.

C) There is enough evidence to support the claim that the proportion of men and women who used their cell phone in an emergency differ significantly (P-value=0.014).

Step-by-step explanation:

A. We have two populations: American men and American women. This are the populations from which we want to infere the difference of means.

B. The estimation of the proportion is already shown in the question:

The proportion of men that sometimes do not drive safely while talking or texting on cell phone is 32%, and the proportion of women that sometimes do not drive safely while talking or texting on cell phone is 25%.

These are unbiased estimators of the populations proportions.

C. This is a hypothesis test for the difference between proportions.

The claim is that the proportion of men and women who used their cell phone in an emergency differ significantly.

Then, the null and alternative hypothesis are:

$H_0: \pi_1-\pi_2=0\\\\H_a:\pi_1-\pi_2\neq 0$

The significance level is 0.05.

The sample 1 (men), of size n1=643 has a proportion of p1=0.71.

The sample 2 (women), of size n2=643 has a proportion of p2=0.77.

The difference between proportions is (p1-p2)=-0.06.

$p_d=p_1-p_2=0.71-0.77=-0.06$

The pooled proportion, needed to calculate the standard error, is:

$p=\dfrac{X_1+X_2}{n_1+n_2}=\dfrac{457+495.11}{643+643}=\dfrac{952}{1286}=0.7403$

The estimated standard error of the difference between means is computed using the formula:

$s_{p1-p2}=\sqrt{\dfrac{p(1-p)}{n_1}+\dfrac{p(1-p)}{n_2}}=\sqrt{\dfrac{0.7403*0.2597}{643}+\dfrac{0.7403*0.2597}{643}}\\\\\\s_{p1-p2}=\sqrt{0.0003+0.0003}=\sqrt{0.0006}=0.0245$

Then, we can calculate the z-statistic as:

$z=\dfrac{p_d-(\pi_1-\pi_2)}{s_{p1-p2}}=\dfrac{-0.06-0}{0.0245}=\dfrac{-0.06}{0.0245}=-2.45$

This test is a two-tailed test, so the P-value for this test is calculated as (using a z-table):

$P-value=2\cdot P(z$

As the P-value (0.014) is smaller than the significance level (0.05), the effect is significant.

The null hypothesis is rejected.

There is enough evidence to support the claim that the proportion of men and women who used their cell phone in an emergency differ significantly.

3 0

4 years ago

Megan went to the store and bought 4 notebooks and 9 pencils for a total of $8.25. Joanne went to the same store and bought 7 no

Rzqust [24]

Let notebooks be x and let pencils be y

4x+9y=8.25 (equation 1)
7x+14y=14.00 (equation 2)

Multiply equation 1 by 7
So that you get 28x+63y=57.75

Multiply equation 2 by 4
So that you get 28x+56y=56.00

28x+63y=57.75 -
28x+56y=56.00
-----------------------
7y=1.75

Divide both sides by 7
1.75/7 is 0.25

So, now we know that one pencil costs 0.25 cents

Sub this y value into equation one

4x+9(0.25)=8.25

4x+2.25=8.25

Move 2.25 to the other side as a negative number

4x= 6

Divide both sides by 4

6/4 is $1.50

So, one pencil is equal to 0.25 cents and one notebook is equal to $1.50

5 0

3 years ago

The population of Mexico in 2000 was approximately 103,970,000 and the land area was 761,700 square miles. The population increa

nata0808 [166]

Answer: 19 people per sqaure mile

Step-by-step explanation:

Given : Population in 2000 = 103,970,000

The population increased by 13.4% in 2010.

Population in 2010 = 103,970,000 + 13.4% of (103,970,000)

= 103,970,000+ (0.134)(103,970,000)

= 103,970,000(1+0.134)

=103,970,000(1.134)

=117,901,980

In 2000,

Population density= $\dfrac{\text{Population}}{\text{Area}}$

$=\dfrac{103970000}{761700}\approx 136\text{ people per square mile}$

In 2010

Population density = $\dfrac{\text{Population}}{\text{Area}}$

$=\dfrac{117901980}{761700}\approx155\text{ people per square mile}$

Difference = 155-136 = 19 people per sqaure mile

Hence, the increase in population density in 2010 = 19 people per sqaure mile

6 0

3 years ago