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3 years ago

I NEED HELP PLEASE !

Mathematics

2 answers:

ikadub [295]3 years ago

8 0

Answer:

I forgot

Explanation:

I did this yesterday

LekaFEV [45]3 years ago

8 0

Answer:

The answer is 75

Step-by-step explanation:

You might be interested in

Amy is 5 years older than Ben. Three times Amy's age added to six times Ben's age is 42. How old are Amy and Ben?

I am Lyosha [343]

Answer:

Amy: 8, Ben: 3

Step-by-step explanation:

No explanation here

5 0

3 years ago

Anna has $430. She wants to buy a phone that costs $275. Anna will also have to pay a sales tax of 7%.

ki77a [65]

19.25 (tax)
294.25 (total price)
135.75 (money left)

REASONING:

In this word problem it says Anna has 430 dollars. The phone costs 275 dollars. It also says that when she buys the phone, she will have to pay a tax of 7%.

To find how much tax she will pay, we must do [275] x [0.07]

After inputting this into a calculator, you will get 19.25 (tax)

To find the total price, all you have to do is add 19.25 to 275. When you do this, you will get 294.25 dollars (total price)

To find how much money she has left,

430-294.25=135.75 (money left)

5 0

3 years ago

64% of 75 tiles is?

noname [10]

$64\% \ of \ 75=64\% \times 75= \frac{64}{100} \times 75=\frac{16}{25} \times 75=16 \times 3=48$

64% of 75 tiles is 48 tiles.

8 0

3 years ago

Read 2 more answers

Many high school students take the AP tests in different subject areas. In 2007, of the 144,796 students who took the biology ex

Nataly [62]

Answer:

$(0.582-0.485) - 1.64 \sqrt{\frac{0.582(1-0.582)}{144796} +\frac{0.485(1-0.485)}{211693}}=0.0942$

$(0.582-0.485) + 1.64 \sqrt{\frac{0.582(1-0.582)}{144796} +\frac{0.485(1-0.485)}{211693}}=0.09978$

And the 90% confidence interval would be given (0.0942;0.09978).

We are confident at 90% that the difference between the two proportions is between $0.0942 \leq p_A -p_B \leq 0.09978$

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$p_A$ represent the real population proportion female for Biology

$\hat p_A =\frac{84199}{144796}=0.582$ represent the estimated proportion female for biology

$n_A=144796$ is the sample size for A

$p_B$ represent the real population proportion female for calculus AB

$\hat p_B =\frac{102598}{211693}=0.485$ represent the estimated proportion female for Calculus AB

$n_B=211693$ is the sample size required for B

$z$ represent the critical value for the margin of error

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

The confidence interval for the difference of two proportions would be given by this formula

$(\hat p_A -\hat p_B) \pm z_{\alpha/2} \sqrt{\frac{\hat p_A(1-\hat p_A)}{n_A} +\frac{\hat p_B (1-\hat p_B)}{n_B}}$

For the 90% confidence interval the value of $\alpha=1-0.90=0.1$ and $\alpha/2=0.05$ , with that value we can find the quantile required for the interval in the normal standard distribution.