Answer:
21.759
Step-by-step explanation:
Given that :
Mean (m) = 25
Standard deviation (s) = 12.5
Sample size (n) = 40
α = 90%
The confidence interval is obtained using the relation:
Mean ± Zcritical * s/sqrt(n)
Zcritical at 90% confidence interval = 1.64
25 ± 1.64 * (12.5/sqrt(40))
Lower boundary : 25 - 1.64(1.9764235) = 21.75866546
Upper boundary : 25 + 1.64(1.9764235) = 28.24133454
(21.759, 28.241)
Hence, lower bound of confidence interval is : 21.759
Hello,
Answer B
x^4-52x²+576=0
==>x^4-16x²-36x²+576=0
==>x²(x²-16)-36(x²-16)=0
==>(x²-16)(x²-36)=0
==>(x+4)(x-4)(x+6)(x-6)=0
Answer:
15
Step-by-step explanation:
|-7-8| = |-15| = 15##
