Answer:
A
Step-by-step explanation:
because the points in the plot point graph are all close to the line which indicates a strong association.
Also the slope isn't closer to 0 than to 1 so that eliminates those answers.
Let x be rate of boat in still water
let y be rate of current
we use this equation to relate quantities:
distance = speed · time
we have two unknowns so we might need to create a system of equationss
upstream:
speed (in km/h) = x - y
(we get speed of boat then subtract the current's speed from it since current is going against boat direction)
time = 3 hours
distance = 144 km
downstream:
speed (in hm/h) = x + y
(we get speed of boat then add the current's spd from it since current is going against boat direction)
time = 2 hours
distance = 144 km (same distance upstream and downstream)
using distance = speed times time
for upstream
144 = 3(x-y)
144 = 3x - 3y
for downstream
144 = 2(x+y)
72 = x + y
system of eqns:
144 = 3x - 3y
72 = x + y
solve by substitution: move 72 = x + y into x = 72 - y and subst into other equation for x
144 = 3(72 - y) - 3y
144 = 216 - 3y - 3y
144 = 216 - 6y
144 - 216 = -6y
-72 = -6y
y = 12 km/h
Use x = 72 - y to find x with y = 12: x = 72 - 12 = 60 km/h
rate of boat in still water is 60 km/h
rate of the current is 12 km/h
Answer:
This statement can be made with a level of confidence of 97.72%.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 8.1 mm
Standard Deviation, σ = 0.5 mm
Sample size, n = 100
We are given that the distribution of thickness is a bell shaped distribution that is a normal distribution.
Formula:
Standard error due to sampling:
P(mean thickness is less than 8.2 mm)
P(x < 8.2)
Calculation the value from standard normal z table, we have,
This statement can be made with a level of confidence of 97.72%.
A quadratic equation has either two different real roots, one real root, or two conjugate complex roots (this is the case when the discriminant is negative, i.e. when you have no real roots).
Two conjugate complex roots have the same real part and opposite imaginary parts. So, the solutions to Amina's equation will be in this form:
For some 
First, you need to put them in order
53kg, 55kg, 61kg, 61kg, 76kg, 91kg, 98kg, 105kg, 120kg
For mean, you add them all up and divide by the amount of numbers (9)
720/9 = 80
For median, you find the middle number (76kg)
For mode, you find the number that appears the most (61kg)
Mean: 80
Median: 76
Mode: 61
