<em>*Remember that A = angle and S = side.</em>
So remember that <u>similar figures have congruent angles and proportional sides.</u> Looking at triangles ABC and DEF, they both share 85° and 30° angles. <u>With this, the two triangles are similar by AA, or the first option.</u>
Answer:
c
Step-by-step explanation:
length times width times height so 4 times 5 times 7 equals 140
Answer:
Ф = 0 and Ф = π
Step-by-step explanation:
* Lets explain how to solve the problem
∵ sin Ф + 1 = cos²Ф, where 0 ≤ Ф < 2π
- To solve we must to replace cos²Ф by 1 - sin²Ф
∵ sin²Ф + cos²Ф = 1
- By subtracting sin²Ф from both sides
∴ cos²Ф = 1 - sin²Ф
- Lets replace cos²Ф in the equation above
∴ sin Ф + 1 = 1 - sin²Ф
- Subtract 1 from both sides
∴ sin Ф = - sin²Ф
- Add sin²Ф for both sides
∴ sin²Ф + sin Ф = 0
- Take sin Ф as a common factor from both sides
∴ sin Ф(sin Ф + 1) = 0
- Equate each factor by 0
∵ sin Ф = 0
∴ Ф = 0 OR Ф = 2π
∵ sin Ф + 1 = 0
- Subtract 1 from both sides
∴ sin Ф = -1
∴ Ф = π
∵ 0 ≤ Ф < 2π
∵ Ф < 2π
∴ We will refused the answer Ф = 2π
∴ Ф = 0 and Ф = π
Answer:
160
Step-by-step explanation:
2² is 4 and the fourth multiple of 10 is 40.
Multiply those numbers together, and you get 160.
Answer: (14.4, 17.2)
Step-by-step explanation: We are to construct a 98% confidence interval for mean household usage of electricity.
We have been given that
Sample size (n) = 872
Sample mean (x) = 15.8
Population standard deviation (σ) = 1.8
The formulae that defines the 98% confidence interval for mean is given below as
u = x + Zα/2 × σ/√n...... For the upper limit
u = x - Zα/2 × σ/√n...... For the lower limit
Zα/2 = critical value for a 2% level of significance in a two tailed test = 2.33
By substituting the parameters we have that
For upper tailed
u = 15.8 + 2.33 × (1.8/√872)
u = 15.8 + 2.33 (0.6096)
u = 15.8 + 1.4203
u = 17.2
For lower tailed
u = 15.8 - 2.33 × (1.8/√872)
u = 15.8 - 2.33 (0.6096)
u = 15.8 - 1.4203
u = 14.4
Hence the 98% confidence interval for population mean usage of electricity is (14.4kwh, 17.2kwh)
