Answer:
97
Step-by-step explanation:
Given that:
Low = 43bpm
High = 115 bpm
Error = 3
α = 90%
To find the range estimate :
Standard destviation = (high - low) / 4
Standard deviation = (115 - 43) / 4
Standard deviation = 72/4 = 18
The sample size,(n) :
n = [(Zα/2 * sd)/E] ²
2 - tail = (Zα/2) = 1.645
[(Zα/2 * sd)/E] ² = [(1.645 * 18) / 3]² = (29.61/3)²
= 97.41
Sample size = 97
Answer:
<h3>2x+2y = 100</h3>
Step-by-step explanation:
Total number of points in the test = 100points
If the test has x questions worth 2 points apiece, then the total number of points for x questions with 2 points each will be 2 * x i.e 2x........ 1
Also, if y questions worth 4 points apiece then the total number of points for y questions with 4 points each will be 4 * x i.e 4x ....... 2
Total points = eqn 1 + eqn 2
100 = 2x+ 2y
Rearrange
2x+2y = 100
Hence an equation in Standard Form that would model this situation is 2x+2y = 100
from the question, (-2,2) and (1,2) have the same y value so you can use that as your base and easily find the perpendicular height using the y axis since it's parallel to the x axis.
the third point, (0,-6), to the base is your height
use the sum of the positive of the y values to find your height (because height can't be negative): 6+2 = 8
area of a triangle = 1/2 bh = 1/2 x 3 x 8 = 12
Note: 1/2 bh only works because (-2,2) and (1,2) form a line parallel to the x axis
A = l x w
225 = l * 13 3/4
225 ÷ 13 3/4 = l * 13 3/4÷ 13 3/4
16 4/11 = l
Length = 16 4/11 inches
