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3 years ago

10

1/3 of your birthday cake is leftover from your party. If you eat 1/4 of the leftover cake, what fraction of the original birthd

ay cake is left

1 answer:

navik [9.2K]3 years ago

3 0

Answer:

a twelth= 1/12

Step-by-step explanation:

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HELLP ME PLS QUICK

MAVERICK [17]

Answer:

Both Oscar and Kim will have enough to purchase the book.

Step-by-step explanation:

Oscar takes 30% of the normal price and subtracts it from the normal price. Out of 100% price he takes 30% so the result is: 100-30%= 70% of the normal price. Oscar's first step has the same result as Kim.

Oscar takes 10% of the discounted price (70%) and adds it back. The price will become 70% + 10%*70%= 77% of original price. Kim multiplies the discounted price with 110%, so the price will be: 70% * 110%= 77%. Both also give the same result.

The final price is 77% of the original, it will be: $28.50* 77%= $21.945

Oscar :

28.50 - 0.30(28.50) = 28.50 - 8.55 = 19.95

0.10(19.95) + 19.95 = 2 + 19.95 = 21.95

Kim :

0.7(28.50) = 19.95

1.10(19.95) = 21.95

7 0

2 years ago

Read 2 more answers

23. A certain type of gasoline is supposed to have a mean octane rating of at least 90. Suppose measurements are taken on of 5 r

Nostrana [21]

Answer:

a) $p_v =P(Z$

b) Since $p_v$ we can reject the null hypothesis at the significance level given. So based on this we can commit type of Error I.

Because Type I error " is the rejection of a true null hypothesis".

c) $P(\bar X >90)=1-P(Z$

$1-P(Z$

d) For this case we need a z score that accumulates 0.02 of the area on the right tail and 0.98 on the left tail and this value is z=2.054

And we can use this formula:

$2.054=\frac{90-89}{\frac{0.8}{\sqrt{n}}}$

And if we solve for n we got:

$n = (\frac{2.054 *0.8}{1})^2=2.7 \approx 3$

Step-by-step explanation:

Previous concepts and data given

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".

We can calculate the sample mean and deviation with the following formulas:

$\bar X = \frac{\sum_{i=1}^n X_i}{n}$

$s=\sqrt{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}$

$\bar X=88.96$ represent the sample mean

$s=1.011$ represent the sample standard deviation

n=5 represent the sample selected

$\alpha$ significance level

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is less than 90, the system of hypothesis would be:

Null hypothesis: $\mu \geq 90$

Alternative hypothesis: $\mu < 90$

If we analyze the size for the sample is < 30 and we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{88.96-90}{\frac{0.8}{\sqrt{5}}}=-2.907$

Part a

P-value

First we need to calculate the degrees of freedom given by:

$df=n-1=5-1 = 4$

Then since is a left tailed test the p value would be:

$p_v =P(Z$

Part b

Since $p_v$ we can reject the null hypothesis at the significance level given. So based on this we can commit type of Error I.

Because Type I error " is the rejection of a true null hypothesis".

Part c

We want this probability:

$P(\bar X$

The best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\frac{\sigma}{\sqrt{n}}}$

If we apply this formula to our probability we got this:

$P(\bar X >90)=1-P(Z$

$1-P(Z$

Part d

For this case we need a z score that accumulates 0.02 of the area on the right tail and 0.98 on the left tail and this value is z=2.054

And we can use this formula:

$2.054=\frac{90-89}{\frac{0.8}{\sqrt{n}}}$

And if we solve for n we got:

$n = (\frac{2.054 *0.8}{1})^2=2.7 \approx 3$

7 0

3 years ago

Figure EFGH on the grid below represents a trapezoidal plate at its starting position on a rotating platform:

Murrr4er [49]

Answer: A is correct

Step-by-step explanation: I took the test and I got 100

4 0

2 years ago

21 POINTS AND BRAINLEIST

noname [10]

Answer: The answer is D The difference between Shelly's and Terrence's total points

Hope this helped and brainleist please

:D

5 0

3 years ago

Read 2 more answers

The annual Gross Domestic Product (GDP) of a country is the value of all of the goods and services produced in the country durin

almond37 [142]

Year        GDP
y           (billion $)

1985       577

1986       577+ 3.2% of 577 = 577 * 1.032

1987       577* 1.032 + 3.2% of 577 * 1.032 = 577 * (1.032)^2

1988       577 * (1.032)^3

1989       577 * (1.032)^4

....           .... => model GDP = 577 * (1.032)^ (y - 1985)

Then, for GDP = $3.4 trillion = $3400 billion =>

3400 = 577 (1.032)^ (y - 1985)

Divide both sides by 577:

(1.032)^ (y - 1985) = 3400 / 577 = 5.892548

Apply logarith to both sides:

(y - 1985) log (1.032) = log 5.892548

=> y - 1985 = log (5.892548) / log(1.032) = 56.3 years

=> y = 1985 + 56.3 = 2041.3

Answer: 2041

8 0

3 years ago