Step-by-step explanation:
log <base a> b = x
means
a^x = b
So
3^2 = x^2+7x+21
x^2 + 7x + 21 - 9 = 0
x^2 + 7x + 12 = 0
(x+3)(x+4)
x = -3 or -4
Answer:
option 3, 900 square units
Step-by-step explanation:
area=20*(32+13)
=900
Answer:
part A is 120
Step-by-step explanation:
6 × 20 = 120
part B
Answer:
8/9
Step-by-step explanation:
p(A/B) = p(A inersect B) / p(B)
Answer:
Step-by-step explanation:
Given that: Training-session duration of female rowers with normal iron status is Normally distributed, with mean 69 minutes and standard deviation 18minutes.
Solution:
z score shows the relationship between sample means. The z score is used to determine by how many standard deviations the raw score is above or below the mean. It is given by the formula:

Given that μ = 69 minutes, σ = 18 minutes, n = 24
For x > 63 minutes:

From the distribution table, P(x > 63) = P(z > -1.63) = 1 - P(z < 1.63) = 1 - 0.0516 = 0.9484