Answer:

Step-by-step explanation:

Answer:
4 hours
Step-by-step explanation:
For three visits, the electrician earned $40 × 3 = $120 in "per-visit" charges. For working x hours, he earned 20x in "per-hour" charges. The total of these came to 50x:
120 +20x = 50x
120 = 30x . . . . . . . . subtract 20x
4 = x . . . . . . . . . . . . . divide by 30
The electrician worked 4 hours that day.
Answer:
1661.06 cm²
Step-by-step explanation:
From the question given above, the following data were obtained:
Radius (r) = 11.5 cm
Size of synthetic leather needed =?
To know how many square centimetres of synthetic leather needed to cover the ball, we shall determine the area of the ball. This can be obtained as follow:
Radius (r) = 11.5 cm
Pi (π) = 3.14
Area of ball =?
The shape of a ball is spherical in nature. Thus, we shall apply the formula for calculating the area of a sphere. This is illustrated below:
A = 4πr²
A = 4 × 3.14 × 11.5²
A = 4× 3.14 × 132.25
A = 1661.06 cm²
Thus, 1661.06 cm² of synthetic leather needed to cover the ball.
Answer:
- 0.9503 ; r is not statistically significant ; 0.9031
Step-by-step explanation:
Given the following :
Age (X) :
37
41
57
65
73
Bone density (Y)
355
345
340
315
310
Using the pearson R value calculator :
The r value of the data % - 0.9503.
This value depicts a very strong negative correlation between age and density of bone.
Using the pearson R calculator to obtain the P- value, the P value obtained is .01332 and hence the r is not significant at P < 0.01.
The Coefficient of determination R^2 can be obtained by getting the square value of R
R^2 = - 0.9503^2
R^2 = 0.90307009
R^2 = 0.9031