Hmmmm...... Are you a 6th grader? I remember doing these in 6th grade.
Answer:
The prevalence of serious defects in this population at the time of birth is 10%.
Step-by-step explanation:
The prevalence of serious defects is the number of infants that were born with seriours birth defects divided by the total number of infants born.
In this problem, we have that:
There were 1000 newborn infants.
100 infants were born with serious birth defects.
Calculate the prevalence of serious defects in this population at the time of birth.
This is:

The prevalence of serious defects in this population at the time of birth is 10%.
The distance between the points A to B is 899.9 feet. After rounding off the nearest integer we get 900 feet as the final answer.
Given we know that CD is perpendicular to AD.
The distance between CD is 139 feet.
As from points A the boat's crew measure the angle of elevation to the beacon as 6°
therefore, m∠A = 6°
Another time the angle of elevation is measured from point B which is 19°.
therefore, m∠DBC = 19°
tan 19° = CD/BD
BD = CD/tan19°
BD = 136/tan 19°
now for tan 6° = CD/AD (tangent is opposite over adjacent)
AD = CD/tan 6°
AD = 136/tan 6°
AB = AD ₋ BD
AB = 136/tan 6° ₋ 136/tan 19°
AB = 1295.2 ₋ 395.3
AB = 900 feet
hence the distance from point A to B is 900 feet.
Learn more about Heights and distances here:
brainly.com/question/2004882
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