Answer:
0.6154 = 61.54% probability that the student is an undergraduate
Step-by-step explanation:
Conditional Probability
We use the conditional probability formula to solve this question. It is

In which
P(B|A) is the probability of event B happening, given that A happened.
is the probability of both A and B happening.
P(A) is the probability of A happening.
In this question:
Event A: Foreign
Event B: Undergraduate.
There are four times as many undergraduates as graduate students
So 4/5 = 80% are undergraduate students and 1/5 = 20% are graduate students.
Probability the student is foreign:
10% of 80%
25% of 20%. So

Probability that a student is foreign and undergraduate:
10% of 80%. So

What is the probability that the student is an undergraduate?

0.6154 = 61.54% probability that the student is an undergraduate
Answer:
243 cm^2 + 108 cm^2 = 351 cm^2
Step-by-step explanation:
So, we have a rectangle and two triangles, we know all the sides or angles.
Rectangle: with 9 cm lenght 15cm + 12 cm = 27 cm
Formula: A=wl -> A=9*27 = 243 cm^2
Trianlge: A=ab/2
Angle 90°
Side A 12 cm
Side B 18 cm - 9 cm = 9 cm
A=ab/2=12·9/2=54 cm times 2 (for the opposite side) = 108 cm^2 = 351 cm^2
Answer:
The 99% confidence interval for the mean commute time of all commuters in Washington D.C. area is (22.35, 33.59).
Step-by-step explanation:
The (1 - <em>α</em>) % confidence interval for population mean (<em>μ</em>) is:

Here the population standard deviation (σ) is not provided. So the confidence interval would be computed using the <em>t</em>-distribution.
The (1 - <em>α</em>) % confidence interval for population mean (<em>μ</em>) using the <em>t</em>-distribution is:

Given:

*Use the <em>t</em>-table for the critical value.
Compute the 99% confidence interval as follows:

Thus, the 99% confidence interval for the mean commute time of all commuters in Washington D.C. area is (22.35, 33.59).
Answer:
the equation should be corrected to fit the data of the problem. With the corrected equation a mass of 0.5 grams remains after 150 years
Step-by-step explanation:
for the mass y( in grams)
y=23* (1/2)^(t/45), t ≥ 0.
the initial mass is at t=0 , then
y= 23 grams → should be 16 grams
half-life from the equation = 45 years → should be 30 years
the correct equation should be
y=16*(1/2)^(t/30), t ≥ 0
then after 150 years → t= 150
y=16*(1/2)^(150/30)= 16*(1/2)^5 = 16/32 = 0.5 grams
then a mass of 0.5 grams remains after 150 years
Answer: 4
Step-by-step explanation:
1 + 3 = 4. this has gotta be one of the hardest questions i've had to answer on this site