Aisha helps out at a petting zoo over the summer. She makes some changes where the animals are kept.

Seven friends want to buy a video game together to share. the cost will be evenly split among them. what is the expression that

Burka [1]

Answer:

the correct answer is D

Step-by-step explanation:

if the 7 friends are splitting the cost they are dividing it among themselves.

4 0

1 year ago

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Ecologists sometimes find rather strange relationships in our environment. For example, do beavers benefit beetles? Researchers

Harman [31]

Answer:

The appropriate conclusion that answers the question stated in step one is:

The weak correlation value does not support the idea that beavers benefit beetles.

The largest number of beetle larvae was 55 and the largest number of stumps was 5.

Step-by-step explanation:

1) Select the appropriate practical question.

The appropriate practical question is:

"How does the number of beaver-caused stumps influences the number of beetle larvae clusters?"

2) Make a scatter plot.

The scatter plot is attached below.

From the scatter plot it can be seen that there exists a negative relationship between beaver stumps and beetle larvae. That is as the number of stumps increases the number of beetle larvae decreases.

The maximum number of beaver stumps found is 5.

3)

The best numerical summary for this problem are,

Correlation and regression line

The least square regression line for predicting the number of beetle larvae from the number of stumps is:

y = 31.594 - 2.8365 x.

Use the Excel function "=CORREL(array1,array2)" to compute the correlation.

The correlation value is, r = -0.219.

Both the correlation coefficient and regression line explains a negative relationship between the number of beetle larvae and the number of stumps.

Values amid 0 and 0.3 (0 and -0.3) implies a weak positive (negative) linear relationship amid the variables.

Thus, a correlation coefficient, r = -0.219, indicates a weak negative correlation between two variables.

Thus, the appropriate conclusion that answers the question stated in step one is:

The weak correlation value does not support the idea that beavers benefit beetles.

The largest number of beetle larvae was 55 and the largest number of stumps was 5.

3 0

2 years ago

Direct Mailing Company sells computers and computer parts by mail. The company claims that more than 90% of all orders are maile

lys-0071 [83]

Answer:

We conclude that less than or equal to 90% of all orders are mailed within 72 hours after they are received which means the company's claim is not true.

Step-by-step explanation:

We are given that the company claims that more than 90% of all orders are mailed within 72 hours after they are received. The quality control department at the company often takes samples to check if this claim is valid.

A recently taken sample of 175 orders showed that 161 of them were mailed within 72 hours.

Let p = percentage of all orders that are mailed within 72 hours.

SO, Null Hypothesis, $H_0$ : p $\leq$ 90% {means that less than or equal to 90% of all orders are mailed within 72 hours after they are received}

Alternate Hypothesis, $H_A$ : p > 90% {means that more than 90% of all orders are mailed within 72 hours after they are received}

The test statistics that will be used here is One-sample z proportion statistics;

T.S. = $\frac{\hat p-p}{{\sqrt{\frac{\hat p(1-\hat p)}{n} } } } }$ ~ N(0,1)

where, $\hat p$ = proportion of orders that were mailed within 72 hours in a sample of 175 = $\frac{161}{175}\times 100$ = 92%

n = sample of orders = 175

So, test statistics = $\frac{0.92-0.90}{{\sqrt{\frac{0.92(1-0.92)}{175} } } } }$

= 0.975

The value of the test statistics is 0.975.

Now at 1% significance level, the z table gives critical value of 2.3263 for right-tailed test. Since our test statistics is less than the critical value of z as 0.975 < 2.3263, so we have insufficient evidence to reject our null hypothesis as it will not fall in the rejection region due to which we fail to reject our null hypothesis.

Therefore, we conclude that less than or equal to 90% of all orders are mailed within 72 hours after they are received which means the company's claim is not true.

6 0

2 years ago

6 pints of a 20 percent solution of alcohol in water are mixed with 4 pints of a 10 percent alcohol in water solution. The perce

andreev551 [17]

Total Volume would be 6 + 4 = 10 pints
Let's calculate the volume of alcohol in final solution:
20% * 6 = 1.2 pints
10% * 4 = .4 pints
Total = 1.6 pints of alcohol in 10
Percentage = (1.6/10) * 100 = 16 per cent.
answer is A

4 0

2 years ago

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Quadrilateral $abcd$ is a trapezoid with $ab$ parallel to $cd$. we know $ab = 20$ and $cd = 12$. what is the ratio of the area o

alekssr [168]

Draw a diagram to illustrate the problem as shown below.

The area of triangle acb is
A₁ = (1/2)*20*h = 10h

The area of trapezoid abcd is
A₂ = (1/2)*(20+12)*h = 16h

The ratio A₁/A₂ is
A₁/A₂ = (10h)/(16) = 5/8

Answer:
The ratio of triangle acb to the area of trapezoid abcd is 5/8.

4 0

2 years ago