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3 years ago

Three hours later than nine o'clock is

2 answers:

8 0

it think the answer is 12:00 am or noon I do t know it depens if you are talking about noon or am okay hope I help and if it didn't I so sorry

olga_2 [115]3 years ago

6 0

12:00 A.M. or P.M. depending on which you are talking about. Therefore either midnight (A.M.) or afternoon ( P.M.).

You might be interested in

The sum of 10 times a number and fifteen is added to 11 times the same number. (how do i make this into a algebraic expression?)

Ne4ueva [31]

10a times (15+11) or 10a times 26

6 0

3 years ago

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

I have 10 shirts, 9 pants, 4 shoes, and 1 hats. How many unique outfits do I have?

lorasvet [3.4K]

360 outfits i think i wouldnt take that as fact tho

3 0

2 years ago

A publisher sells 10⁶ copies of a new book. Each book sells 10² pages. How many pages total are there in all of the books sold?

KatRina [158]

Answer:

10^12.

Step-by-step explanation:

You need to solve 10^6 * 10^2 without using standard notation. As with variables, if you had x^6 * x^2 you would add the exponents. Replace x with 10. Your answer is 10^8. As a sidenote, only multiply exponents when raising a power to another power, e.g. (10^6)^2 = 10^12.

3 0

3 years ago

Read 2 more answers

what is the answer to this question: Tadeo volunteered at the library 6 times as many hours over the weekend as Dylan. Together,

monitta

Answer:

Tadeo: 12 hours
Dylan: 2 hours

Step-by-step explanation:

We can let d represent the number of hours that Dylan volunteered. Then Tadeo volunteered for 6d hours, and their total hours were ...

d +6d = 14

7d = 14 . . . . . . collect terms

d = 2 . . . . . . . divide by the coefficient of d

6d = 6(2) = 12

Tadeo volunteered 12 hours; Dylan volunteered 2 hours.

4 0

2 years ago