Answer: the sample size should be 39
Step-by-step explanation:
The sample mean is the point estimate for the population mean. Confidence interval is written as
Sample mean ± margin of error
Margin of error = z × σ/√n
Where
σ = population standard Deviation
n = number of samples
z represents the z score corresponding to the confidence level
From the information given,
σ = 4 minutes
Margin of error = 75 seconds. Converting to minutes, it becomes 75/60 = 1.25 minutes
To determine the z score, we subtract the confidence level from 100% to get α
α = 1 - 0.95 = 0.05
α/2 = 0.05/2 = 0.025
This is the area in each tail. Since we want the area in the middle, it becomes
1 - 0.025 = 0.975
The z score corresponding to the area on the z table is 1.96. Thus, confidence level of 95% is 1.96
Therefore,
1.25 = 1.96 × 4/√n
1.25/1.96 = 4/√n
0.6378 = 4/√n
√n = 4/0.6378 = 6.27
n = 6.27² = 39
Step-by-step explanation:
For no. 11
13x + 15 = 19x - 9 ( being opposite sides of parallelogram)
19x - 13x = 15 + 9
6x = 24
x = 4
Also,
4y + 7 ° + 10y - 37° = 180° { being co-interior angles }
14y - 30° = 180°
14y = 210°
y = 210° / 14
y = 15°
For no. 12
5x + 38° = 8x - 19° { being opposite angles of parallelogram }
8x - 5x = 38° + 19°
3x = 57°
x = 19°
Hope it will help :)
Answer:
3
Step-by-step explanation:
because its is like subtacting
Answer:
5/3
Step-by-step explanation:
Tangent is defined as the length of the opposite side of the triangle divided by the length of the adjacent side of the triangle. Since you know that two of the legs are 3 and 4, using the pythagorean theorem you know that the last side is 5. Sin is defined as the length of the opposite side divided by the length of the hypotenuse, which in this case is 3/5. Cosecant is just the reciprocal of that, or 5/3. Hope this helps!
Answer:
can you make it more visible
Step-by-step explanation:
