What is another way to write the time "quarter till 8"?

A manager of a grocery store wants to determine if consumers are spending

ololo11 [35]

Answer:

1. The error in the assumption is taking the sample mean, $\bar x$ , as being equal to the population mean, μ

2. To correct the error, the manager will need to generate the confidence interval based on the population standard deviation on the acceptable values of the mean using the following relation;

$CI=\bar{x}\pm z\frac{\sigma}{\sqrt{n}}$

Step-by-step explanation:

We note that from the central limit theorem as the size of the sample, n, becomes more and more larger, the mean of the sample, $\bar x$ , approaches that of the population mean, μ, therefore as the grocery store manager uses the sample mean as the population mean's point estimate an error will be observed based on the size of the sample compared to the population, where the difference between the two means (the population mean and the sample mean) is $\left | \bar{x} - \mu \right |$

1. The error in the assumption is taking the sample mean, $\bar x$ , as being equal to the population mean, μ

2. To correct the error, the manager will need to generate the confidence interval based on the population standard deviation on the acceptable values of the mean using the following relation;

$CI=\bar{x}\pm z\frac{\sigma}{\sqrt{n}}$

Where:

σ = Population standard deviation = $30

z = z value at 95% confidence level = 1.96

$\bar x$ = Sample mean $160

n = Sample size = 10

Plugging in the values, we have;

$141.4 < $\bar x$ < $178.6

Hence the expected value of the mean should be between $141.4 and $178.6.

7 0

3 years ago

Celik, S. (2011). A media comparison study on first aid instruction. Health Education Journal. 72(1), 95-101

aniked [119]

Answer:

The answer is "Option a".

Step-by-step explanation:

In the given scenario, The appropriate test for the teaching profession's accomplishment pre and post-class would be the two-sample t-test with dependent samples, that's why choice "a" is correct.

7 0

3 years ago

What is 15/100 in simplest form

lara [203]

To make a fraction into simplest form you have to find the greatest common factor. In this case it is 5. So then you divide both the numerator and the denominator by the greatest common factor of 5.
15÷5=3
100÷5=20
There is no factors that go into both 3 and 20 so simplest form is 3/20.

5 0

3 years ago

Read 2 more answers

A radio telescope has a parabolic surface, as shown below.

krek1111 [17]

OK, so the graph is a parabola, with points x=0,y=0; x=6,y=-9; and x=12,y=0

Because the roots of the equation are 0 and 12, we know the formula is therefore of the form

y = ax(x - 12), for some a

So put in x = 6

-9 = 6a(-6)

9 = 36a

a = 1/4

So the parabola has a curve y = x(x-12) / 4, which can also be written y = 0.25x² - 3x

The gradient of this is dy/dx = 0.5x - 3

The key property of a parabolic dish is that it focuses radio waves travelling parallel to the y axis to a single point. So we should arrive at the same focal point no matter what point we chose to look at. So we can pick any point we like - e.g. the point x = 4, y = -8

Gradient of the parabolic mirror at x = 4 is -1

So the gradient of the normal to the mirror at x = 4 is therefore 1.

Radio waves initially travelling vertically downwards are reflected about the normal - which has a gradient of 1, so they're reflected so that they are travelling horizontally. So they arrive parallel to the y axis, and leave parallel to the x axis.

So the focal point is at y = -8, i.e. 1 metre above the back of the dish.

5 0

2 years ago

Here are summary statistics for randomly selected weights of newborn girls: nequals202, x overbarequals28.3 hg, sequals6.1 hg

Lorico [155]

Answer:

The confidence interval is 27.5 hg less than mu less than 29.1 hg

(A) Yes, because the confidence interval limits are not similar.

Step-by-step explanation:

Confidence interval is given as mean +/- margin of error (E)

mean = 28.3 hg

sd = 6.1 hg

n = 202

degree of freedom = n-1 = 202-1 = 201

confidence level (C) = 95% = 0.95

significance level = 1 - C = 1 - 0.95 = 0.05 = 5%

critical value corresponding to 201 degrees of freedom and 5% significance level is 1.97196

E = t×sd/√n = 1.97196×6.1/√202 = 0.8 hg

Lower limit = mean - E = 28.3 0.8 = 27.5 hg

Upper limit = mean + E = 28.3 + 0.8 = 29.1 hg

95% confidence interval is (27.5, 29.1)

When mean is 28.3, sd = 6.1 and n = 202, the confidence limits are 27.5 and 29.1 which is different from 27.8 and 29.6 which are the confidence limits when mean is 28.7, sd = 1.8 and n = 17

7 0

3 years ago

What is another way to write the time "quarter till 8"?​

What is another way to write the time "quarter till 8"?