Taking a test!!! I need help on it pleaseee!!!

NEED HELP!! I WILL MARK BRAINLIEST!!!

kipiarov [429]

Answer:

A I think hope its help 0n-''

5 0

3 years ago

Amelia, Luis, Shauna, and Clarence used different approaches to solve the inequality

mezya [45]

Answer:

Luis’s, because he flipped the inequality sign when he subtracted

Step-by-step explanation:

7.2b + 6.5 > 4.8b – 8.1.

Amelia started by subtracting 7.2b from both sides to get

6.5 > –2.4b – 8.1

Correct

Luis started by subtracting 4.8b from both sides to get

2.4b + 6.5 < – 8.1

Incorrect

Shauna started by subtracting 6.5 from both sides to get

7.2b > 4.8b – 14.6

Correct

Clarence started by adding 8.1 to both sides to get

7.2b + 14.6 > 4.8b

Correct

Luis’s is incorrect because he flipped the inequality sign when he subtracted

6 0

3 years ago

At George Washington High School the ratio of graduating seniors that go on to college, as compared to those who do not, is 7 :

soldi70 [24.7K]

First you figure out that the ratio 7:4 is 1.75
Then you do this problem 28 divided by 1.75=16
And 28:16 is the same as 7:4
Now all you do is add 28+16=44

6 0

3 years ago

The cost per student of a ski trip varies inversely as the number of students who attend. It will cost each student $250 if 24 s

mars1129 [50]

ANSWER

30 students

EXPLANATION

The cost per student varies inversely as the number of students.

Inverse proportion is written as:

$\begin{gathered} y\propto\frac{1}{x} \\ y=\frac{k}{x} \\ \text{where k = constant of proportionality} \end{gathered}$

Let the cost per student be y.

Let the number of students be x.

It will cost each student $250 if 24 students attend. This means that:

$\begin{gathered} 250=\frac{k}{24} \\ \Rightarrow k=250\cdot24 \\ k=6000 \end{gathered}$

If the cost is down to $200, it means that y is now $200.

That is:

$\begin{gathered} 200=\frac{6000}{x} \\ \Rightarrow x=\frac{6000}{200} \\ x=30\text{ students} \end{gathered}$

Therefore, 30 students could attend.

5 0

2 years ago

A company surveyed 2400 men where 1248 of the men identified themselves as the primary grocery shopper in their household. a) E

polet [3.4K]

Answer:

a) With a confidence level of 98%, the percentage of all males who identify themselves as the primary grocery shopper are between 0.4962 and 0.5438.

b) The lower limit of the confidence interval is higher that 0.43, so if he conduct a hypothesis test, he will find that the data shows evidence to said that the fraction is higher than 43%.

c) $\alpha =1-0.98=0.02$

Step-by-step explanation:

If np' and n(1-p') are higher than 5, a confidence interval for the proportion is calculated as:

$p'-z_{\alpha/2}\sqrt{\frac{p'(1-p')}{n} }\leq p\leq p'+z_{\alpha/2}\sqrt{\frac{p'(1-p')}{n} }$

Where p' is the proportion of the sample, n is the size of the sample, p is the proportion of the population and $z_{\alpha/2}$ is the z-value that let a probability of $\alpha/2$ on the right tail.

Then, a 98% confidence interval for the percentage of all males who identify themselves as the primary grocery shopper can be calculated replacing p' by 0.52, n by 2400, $\alpha$ by 0.02 and $z_{\alpha/2}$ by 2.33

Where p' and $\alpha$ are calculated as:

$p' = \frac{1248}{2400}=0.52\\\alpha =1-0.98=0.02$

So, replacing the values we get:

$0.52-2.33\sqrt{\frac{0.52(1-0.52)}{2400} }\leq p\leq 0.52+2.33\sqrt{\frac{0.52(1-0.52)}{2400} }\\0.52-0.0238\leq p\leq 0.52+0.0238\\0.4962\leq p\leq 0.5438$

With a confidence level of 98%, the percentage of all males who identify themselves as the primary grocery shopper are between 0.4962 and 0.5438.

The lower limit of the confidence interval is higher that 0.43, so if he conduct a hypothesis test, he will find that the data shows evidence to said that the fraction is higher than 43%.

Finally, the level of significance is the probability to reject the null hypothesis given that the null hypothesis is true. It is also the complement of the level of confidence. So, if we create a 98% confidence interval, the level of confidence $1-\alpha$ is equal to 98%

It means the the level of significance $\alpha$ is:

$\alpha =1-0.98=0.02$

4 0

3 years ago