Answer:
n=6.25
Step-by-step explanation:
9n-6=5n+18
9n=5n+25
4n=25
n=6.25
Answer:4.6
Step-by-step explanation:
Percentage decrease=(65-62)/65 x 100
Percentage decrease=3/65 x 100
Percentage decrease=(3x100)/65
Percentage decrease=300/65
percentage decrease=4.6
Answer:
0.6247
Step-by-step explanation:
In order to find the frequency of people who complete the test between 45 and 65 minutes, we have to find z
Z = (x – mean)/standard deviation
Le x be the time to complete the test
Z1 = (45 – 60)/10 = -1.5
Z2 = (65 – 60)/10 = 0.5
Then we use the z table to find the area under the curve.
Area for Z1 = 0.4332
Area for Z2 = 0.1915
The relative frequency is the area between the two z-scores:
0.4332 +0.1915 = 0.6247
Graphic with shaded area is attached