Answer:
P(a junior or a senior)=1
Step-by-step explanation:
The formula of the probability is given by:
P (AB) = P(A)
Where P(A) is the probability of occurring an event A, n(A) is the number of favorable outcomes and N is the total number of outcomes.
In this case, N is the total number of the students of statistics class.
N=18+10=28
The probability of the union of two mutually exclusive events is given by:
Therefore:
P(a junior or a senior) =P(a junior)+P(a senior)
Because a student is a junior or a senior, not both.
n(a junior)=18
n(a senior)=10
P(a junior)=18/28
P(a senior) = 10/28
P(a junior or a senior) = 18/28 + 10/28
Solving the sum of the fractions:
P(a junior or a senior) = 28/28 = 1
Answer:
z = 2.1
Step-by-step explanation:

This tells us that the person's score of 121 places them 2.1 standard deviations above the mean score of 79.
Answer:
420 minutes
Step-by-step explanation:
1 hour = 60 minutes
7 * 1 hour = 7 * 60 minutes
7 hours = 420 minutes
The answer is 18 inches.
432 / 24 = 18
area / length = width