Answer:
Step-by-step explanation:
We are looking for P(58 < x < 64). We need to find the percentage to the left of the z-scores for each of these numbers. To find the z scores, use the formula:
which gives us a z-score of -1. The percentage of numbers to the left of a z-score of -1 is .1586553
Now for the other z-score:
which gives us a z-score of .5. The percentage of numbers to the left of a z-score of .5 is .69146246
The lower percentage subtracted from the higher gives the area in question:
.69146246 - .1586553 = .53280716, or as a percentage, 53.3%, choice A.
Answer:
(x + 5)² + (y + 7)² = 288
Step-by-step explanation:
The equation of a circle in standard form is
(x - h)² + (y - k)² = r²
where (h, k) are the coordinates of the centre and r is the radius
The radius is the distance from the centre (- 5, - 7) to the point on the circle (7, 5)
Use the distance formula to calculate r
r = √ (x₂ - x₁ )² + (y₂ - y₁ )²
with (x₁, y₁ ) = (- 5, - 7) and (x₂, y₂ ) = (7, 5)
r = =
=
Hence
(x - (- 5))² + (y - (- 7))² = ()², that is
(x + 5)² + (y + 7)² = 288