South Africa broke the world record for largest pizza in 1990. It weighed `26833` pounds

A standard weight known to weigh 10 grams. Some suspect bias in weights due to manufacturing process. To assess the accuracy of

notsponge [240]

Answer:

a) The 98% confidence interval for the mean weight is between 10.00409 grams and 10.00471 grams

b) 49 measurements are needed.

Step-by-step explanation:

Question a:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.98}{2} = 0.01$

Now, we have to find z in the Ztable as such z has a pvalue of $1 - \alpha$ .

That is z with a pvalue of $1 - 0.01 = 0.99$ , so Z = 2.327.

Now, find the margin of error M as such

$M = z\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

$M = 2.327\frac{0.0003}{\sqrt{5}} = 0.00031$

The lower end of the interval is the sample mean subtracted by M. So it is 10.0044 - 0.00031 = 10.00409 grams

The upper end of the interval is the sample mean added to M. So it is 10 + 0.00031 = 10.00471 grams

The 98% confidence interval for the mean weight is between 10.00409 grams and 10.00471 grams.

(b) How many measurements must be averaged to get a margin of error of +/- 0.0001 with 98% confidence?

We have to find n for which M = 0.0001. So

$M = z\frac{\sigma}{\sqrt{n}}$

$0.0001 = 2.327\frac{0.0003}{\sqrt{n}}$

$0.0001\sqrt{n} = 2.327*0.0003$

$\sqrt{n} = \frac{2.327*0.0003}{0.0001}$

$(\sqrt{n})^2 = (\frac{2.327*0.0003}{0.0001})^2$

$n = 48.73$

Rounding up

49 measurements are needed.

7 0

3 years ago

Subsubstitution solving for x

yuradex [85]

y = 8x - 18

2x - 8(8x - 18) = 20

2x + -64x + 144 = 20

-62x + 144 = 20

-62x = -124

x = 2

6 0

3 years ago

What is the discriminant of 32x-4= 4x^2 + 60

hodyreva [135]

Step One

Begin by getting one side of the question equal to zero.

32x -4 = 4x^2 + 60 Add - 32x + 4 from both sides.

0 = 4x^2 + 60 - 32x + 4 Collect like terms.

0 = 4x^2 - 32x + 64

Step Two

For this question, you could divide both sides by 4. It just makes the steps later on easier.

0 = x^2 - 8x + 16

Step Three

Calculate the discriminate.

The discriminate is b^2 - 4*a*c

a = 1; b = -8; c = 16

b^2 - 4*a*c = (-8)^2 - 4*(1)(16) = 64 - 64 = 0

There is only 1 root. It is real and it is rational.

A <<<<< Answer

4 0

3 years ago

if your average stride length is 2.6 feet how many strides will it take you to walk to grandparents house

IceJOKER [234]

The distance from your house to your grandparents house is 3.67 miles or 19377.6 ft.

So the total number of strides needed would be:

strides needed = 19377.6 ft / (2.6 ft / stride)

<span>strides needed = 7,452.92 = 7,453 strides</span>

3 0

4 years ago

Please help me do #59

Svetach [21]

Answer:

So the perimeter is 2(16+x) or 32+2x. The area is 8(x+8) or 8x+64.

Step-by-step explanation:

8 0

3 years ago