We cannot calculate the confidence interval without the sample size. However, for the second question, the sample size needed would be 49.

The formula we use is

$n=(\frac{z_{\frac{\alpha}{2}}\times \sigma}{E})^2$

To find the z-score:
Convert 98% to a decimal: 0.98
Subtract from 1: 1-0.98 = 0.02
Divide by 2: 0.02/2 = 0.01
Subtract from 1: 1-0.01 = 0.99

Using a z-table (http://www.z-table.com) we see that this value is closest to a z-score of 2.33.

Using the z-score, our standard deviation (9) and our margin of error (3), we have:
$n=(\frac{2.33(9)}{3})^2=(6.99)^2=48.86\approx 49$

6 0

3 years ago

Please help I’ll give brainlyest

GrogVix [38]

Answer:

80m^3

Step-by-step explanation:

Here,
For the base of pyramid which is a rectangle,
length(a) = 8m
breadth(c) = 5m
For the pyramid,
actual height (h) = 6m
Now,
The formula for the Volume of a rectangular based pyramid is,
1/3 * Area of base rectangle * height
= 1/3 * (a*c) * 6 [ Because area of rectangle is product of its two sides, length and breadth]
= 2 * 8 * 5
80m^3

6 0

2 years ago