Answer:
<h2>
there are 300 girls</h2>
Step-by-step explanation:
a. Find the probability that an individual distance is
greater than 214.30 cm
We find for the value of z score using the formula:
z = (x – u) / s
z = (214.30 – 205) / 8.3
z = 1.12
Since we are looking for x > 214.30 cm, we use the
right tailed test to find for P at z = 1.12 from the tables:
P = 0.1314
b. Find the probability that the mean for 20 randomly
selected distances is greater than 202.80 cm
We find for the value of z score using the formula:
z = (x – u) / s
z = (202.80 – 205) / 8.3
z = -0.265
Since we are looking for x > 202.80 cm, we use the
right tailed test to find for P at z = -0.265 from the tables:
P = 0.6045
c. Why can the normal distribution be used in part (b),
even though the sample size does not exceed 30?
I believe this is because we are given the population
standard deviation sigma rather than the sample standard deviation. So we can
use the z test.
Answer:10
Step-by-step explanation: substitution = 2(25-10)/3
25-10 =15
15*2=30
30/3=10
Answer =10
Roots of the polynomial are values of x when f(x)=0,so
to find the roots of the polynomial we need to solve the equation
x²+9x-70=0 , a=1, b=9,c=-70