Answer:
option (c) The mean age will stay the same but the variance will decrease
Step-by-step explanation:
Case I: For 3 executives of ages 56, 57 and 58
Number of executives, n = 3
Mean =
or
Mean = 57
Variance =
or
Variance =
or
Variance =
or
Variance = 1
For Case II: For 4 executives of ages 56, 57, 58 and 57
Number of executives, n = 4
Mean =
or
Mean = 57
Variance =
or
Variance =
or
Variance =
or
Variance = 0.67
Hence,
Mean will remain the same and the variance will decrease
Hence,
The correct answer is option (c) The mean age will stay the same but the variance will decrease
Answer:
1 hour and 15 minutes
Step-by-step explanation:
Answer:
Option B. The equation has a maximum value with a y-coordinate of -21.
Step-by-step explanation:
The correct quadratic equation is

This is a vertical parabola open downward (the leading coefficient is negative)
The vertex represent a maximum
Convert to vertex form
Factor -3

Complete the square


Rewrite as perfect squares

The vertex is the point (2,-21)
therefore
The equation has a maximum value with a y-coordinate of -21