A standard fire hose is 50 feet long. What is the length of the hose in yards and feet?

A population has a mean of 300 and a standard deviation of 18. A sample of 144 observations will be taken. The probability that

erastova [34]

Answer:

0.8664

Step-by-step explanation:

I hope it helps, and please give me Brainlest!

3 0

3 years ago

Someone help please!!

vazorg [7]

Answer:

Combine like terms:

(5) (-a +4a)

5 + 3a

5 0

3 years ago

Read 2 more answers

A classic rock radio station claims to play an average of 50 minutes of music every hour. However, it seems that every time you

tia_tia [17]

Answer:

a) $47.917-1.796\frac{2.811}{\sqrt{12}}=46.460$

$47.917+1.796\frac{2.811}{\sqrt{12}}=49.374$

b) Null hypothesis: $\mu =50$

Alternative hypothesis: $\mu \neq 50$

And after analyze the interval obtained the upper limit not contains the value of 50, so then we can conclude that the claim is not satisfied for this case, and the population mean seems to be lower than 50 at 10% of significance.

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".

We have the following data: 44 49 45 51 49 53 49 44 47 50 46 48

And we can calculate the sample mean and deviation with the following formulas:

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

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

And replacing we got:

$\bar X= 47.917, s= 2.811$

$\mu$ population mean (variable of interest)

n=12 represent the sample size

Part a: Calculate the confidence interval

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

The degrees of freedom are given:

$df= n-1= 12-1=11$

Since the Confidence is 0.90 or 90%, the value of $\alpha=0.1$ and $\alpha/2 =0.05$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.05,11)".And we see that $t_{\alpha/2}=1.796$

Now we have everything in order to replace into formula (1):

$47.917-1.796\frac{2.811}{\sqrt{12}}=46.460$

$47.917+1.796\frac{2.811}{\sqrt{12}}=49.374$

Part b

For this case the system of hypothesis are:

Null hypothesis: $\mu =50$

Alternative hypothesis: $\mu \neq 50$

And after analyze the interval obtained the upper limit not contains the value of 50, so then we can conclude that the claim is not satisfied for this case, and the population mean seems to be lower than 50 at 10% of significance.

6 0

3 years ago

Consider all four-digit numbers that can be made from the digits 0-8 (assume that numbers cannot start with 0). What is the prob

vodomira [7]

Answer:

0.2498

Step-by-step explanation:

Number of 4 digit numbers that can be formed from the digit (0 - 8), assume number can't start from 0

Thus ;

First digit = (1, 2, 3, 4, 5, 6, 7, 8) = 8 ways

Next three digits = (0, 1, 2, 3, 4, 5, 6, 7, 8) = 9 ways

Hence,

Total possible outcomes = sample space = (8 * 9 * 9 * 9) = (8 * 9^3 ) = 8 * 729 = 5832

Required = number greater Than 7000

For number to be greater Than 7000, starting digit should be either 7 or 8

Hence,

First digit = 2 ways

Next three digits = 9 ways

Also excluding 7000

Hence, Number of digits above 7000;

2 * 9^3 = 2 * 729 = 1458 - 1 = 1457

Hence,

Probability = 1457 / 5832

= 0.2498285

= 0.2498

7 0

3 years ago

Which expressions are equivalent to 2(4f + 2g)?

andreyandreev [35.5K]

Answer:

For example, 8f + 4g is one of the most used expression

Another example is 4 (2f + g), is correct too

8 0

2 years ago