Answer:
The second and the last options.
Step-by-step explanation:
15/ 2/9 =67.5 Solve the original problem
15*2/9 =3.33333333333
15*9/2 =67.5
(15* 1/9) /2=0.833333333333333
15*9* 1/2 =67.5
Answer:3/20
Step-by-step explanation:
Heads=Boy
Tails=Girl
If the first 3 students are boys, all 3 coins must be heads.
Because in 3 of these experiments, the coins all land on heads, and there are 20 experiments completed, 3 out of the 20 experiments are 3 boys; 3/20.
Solve by using the quadratic formula.
x=1+-i√5 / 6
Answer:
4
Step-by-step explanation:
Answer:
0.2805
Step-by-step explanation:
Given that p = 20% = 0.2, n = 300.
The mean (μ) = np = 0.2 * 300 = 60
The standard deviation (σ) = 
The z score is used to determine by how many standard deviations the raw score is above or below the mean. The z score is given by:

For x = 57:

For x = 62:

From the normal distribution table, P(57 < x < 62) = P(-0.43 < z < 0.29) = P(z < 0.29) - P(z < -0.43) = 0.6141 - 0.3336 = 0.2805