Factor the polynomial 64x^3-125

A survey of 100 similar-sized hospitals revealed a mean daily census in the pediatrics service of 27 with a standard deviation o

Vinil7 [7]

Answer:

We conclude that the mean is greater than 25.

Step-by-step explanation:

We are given the following in the question:

Population mean, μ = 25

Sample mean, $\bar{x}$ = 27

Sample size, n = 100

Alpha, α = 0.05

Sample standard deviation, s = 6.5

First, we design the null and the alternate hypothesis

$H_{0}: \mu = 25\\H_A: \mu> 25$

We use One-tailed(right) z test to perform this hypothesis.

Formula:

$z_{stat} = \displaystyle\frac{\bar{x} - \mu}{\frac{s}{\sqrt{n}} }$

Putting all the values, we have

$z_{stat} = \displaystyle\frac{27 - 25}{\frac{6.5}{\sqrt{100}} } = 3.07$

Now, $z_{critical} \text{ at 0.05 level of significance } = 1.645$

Since,

$z_{stat} > z_{critical}$

We reject the null hypothesis and accept the alternate hypothesis.

Thus, the mean is greater than 25.

3 0

3 years ago

g You are planning an opinion study and are considering taking an SRS of either 200 or 600 people. Explain how the sampling dist

Katen [24]

Answer:

By the Central Limit Theorem, both would be approximately normal and have the same mean. The difference is in the standard deviation, since as the sample size increases, the standard deviation decreases. So the SRS of 600 would have a smaller standard deviation than the SRS of 200.

Step-by-step explanation:

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For the sampling distribution of size n of a sample proportion p, the mean is p and the standard deviation is $s = \sqrt{\frac{p(1-p)}{n}}$

Differences between SRS of 200 and of 600

By the Central Limit Theorem, both would be approximately normal and have the same mean. The difference is in the standard deviation, since as the sample size increases, the standard deviation decreases. So the SRS of 600 would have a smaller standard deviation than the SRS of 200.

6 0

3 years ago

A granite block in the shape of a right rectangular

Gnesinka [82]

Answer:

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

Select all the exspressions that are all equivalent to 20 percent of 150

Dmitriy789 [7]

Note: It seems you may have unintentionally missed adding the answer choices. Thus, I am solving your question in general to give you the idea of how the percentage works, which anyways would solve your query.

Answer:

Please check the explanation.

Step-by-step explanation:

Given that we have to determine the expressions which are equivalent to 20 percent of 150.

First, we need to determine what actually 20 percent of 150 really brings.

i.e

20% of 150 = 20/100 × 150

= 30

Thus,

20% of 150 = 30

Therefore, any expression that is equivalent to 30 will be included in the answer to this question.

4 0

2 years ago

X + Y is equal to 5 x minus Y is equal to 4 find the value of find the value of x square minus y square

Grace [21]

Answer: 20

Step-by-step explanation:

x+y=5

x-y=4

---------

x+y=5

x=4+y

--------

(4+y)+y=5

4+y+y=5

4+2y=5

2y=1

y=0.5

x=4.5

---------

x²-y²=(4.5)²-(0.5)²=20.25-0.25=20

7 0

3 years ago