Answer: 106.5
Step-by-step explanation:
We know that, Confidence interval for population mean is given by :-
( Sample mean - Margin of error , Sample mean + Margin of error)
Given: confidence interval is (92.3, 120.7).
i.e. Sample mean - Margin of error = 92.3 (i)
Sample mean + Margin of error = 120.7 (ii)
Adding (i) and (ii) , we get
2( Sample mean ) = 213
⇒ Sample mean = 106.5
Hence, the sample mean = 106.5
1 is C and 2 is D please say thanks
Answer:
6) F
7) B
Step-by-step explanation:
6)
60= 2[½(n -6) +2n +5]
Expand:
60= 2(½)(n -6) +2(2n) +2(5)
60= n -6 +4n +10
Simplify:
60= 5n +4
Minus 4 on both sides:
5n= 60 -4
5n= 56
Divide both sides by 5:
n= 56 ÷5
n= 11.2
Thus, option F is correct.
7)
13q +2= 9(q +6)
Expand:
13q +2= 9q +54
Bring q terms to one side, constant to the other:
13q -9q= 54 -2
Simplify:
4q= 52
Divide both sides by 4:
q= 52 ÷4
q= 13
Thus, option B is correct.
Answer:
{12, 13}
Step-by-step explanation:
Whole numbers that round to 50 will be in the range 45 to 54. Multiples of 4 in that range are 48 and 52.
48 = 4·12
52 = 4·13
Dev's number could be either 12 or 13.
Step-by-step explanation:
1) The first term is -1352, and the common difference is 18. So the 87th term is:
a = -1352 + 18 (87 − 1)
a = 196
2) 1/64 + 1/16 + 1/4 + 1 + 4
This is a geometric series, where the first term is 1/64 and the common ratio is 4.
∑⁵ᵢ₌₁ 1/64 (4)ⁱ⁻¹
Since 1/64 = 4⁻³:
∑⁵ᵢ₌₁ 4⁻³ (4)ⁱ⁻¹
∑⁵ᵢ₌₁ (4)ⁱ⁻⁴
3) The first term is -2100, and the common ratio is -0.1, so the 7th term is:
a = -2100 (-0.1)⁷⁻¹
a = -0.0021
4) The first term is 48, and the fifth term is 243/16, so the common ratio is:
243/16 = 48 r⁵⁻¹
81/256 = r⁴
r = 3/4
So the sequence is:
48, 36, 27, 81/4, 243/16