Answer: The equations are
6x - 6y = 9
4x + 4y = 9
Step-by-step explanation:
Let x represent the speed of the row boat in still water.
Let y represent the speed of the current.
Dana can travel 9 miles in her rowboat in 6 hours against the current. This means that the total speed at which she travelled is
(x - y) miles per hour.
Distance = speed × time
Distance travelled against the current is expressed as
9 = 6(x - y)
6x - 6y = 9
With the current, it takes 4 hours to row the same distance. This means that the total speed at which she travelled is
(x + y) miles per hour.
Distance travelled with the current is expressed as
9 = 4(x + y)
4x + 4y = 9
Answer:
The answer is below
Step-by-step explanation:
Given that:
mean (μ) = 70 years, standard deviation (σ)= 5.5 years.
a) The z score measures how many standard deviation a raw score is above or below the mean. It is given as:
, for a sample size of n, the z score is: 
Given a sample of 5 turtles, we have to calculate the z score for x = 60 and x = 80.
For x = 60:
For x = 80:
The probability that a mean life of a random sample of 5 such turtles falls between 60 and 80 years = P(60 < x < 80) = P(-4.07 < z < 4.07) = P(z < 4.07) - P(z < -4.07) = 1 - 0 = 1 = 100%
b) The z score that corresponds to top 10% is -1.28.
8 t ^ 2 + 4 t ^ 2 - 8 4 t
Answer:
0.95988 (Accuracy of the test )
Step-by-step explanation:
To determine the accuracy of this test we have to list out the given values
Prevalence rate of the disease = 0.3% = 0.003
sensitivity rate of the disease = 92% = 0.92
specificity rate for the test = 96% = 0.96
The accuracy of the test can be found using this equation
Accuracy = sensitivity * prevalence + specificity ( 1 - prevalence )
= 0.92 * 0.003 + 0.96 ( 1 - 0.003 )
= 0.00276 + 0.95712
= 0.95988
Answer:
B. DC = 29 and DE = 44.5
Step-by-step explanation:
I honestly don't know how to get DE but because DC has to be 29, the second option is the only right answer
