Answer:
1655
Step-by-step explanation:
Note the common difference d between consecutive terms of the sequence
d = - 1 - (- 4) = 2 - (- 1) = 5 - 2 = 8 - 5 = 3
This indicates the sequence is arithmetic with sum to n terms
= 
[ 2a₁ + (n - 1)d ]
Here a₁ = - 4, d = 3 and n = 90, thus
= 
[ (2 × - 4) + (89 × 3) ] = 45(- 8 + 267) = 45 × 259 = 1655
The correct answer is: [C]: " c(x) = –8x²<span> + 3x – 5 " .
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The quadratic function takes the form of:
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" f(x) = ax</span>² + bx + c " .
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Answer choice: [C]: " c(x) = –8x² + 3x – 5 " ;
is the only answer choice provided that takes that form of the quadratic function:
" f(x) = ax² + bx + c " :
in which: " a = -8 " ; " b = 3 " ; " c = -5 " .
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84+92+87+104=367
500-367=133
He needs to plant 133 shrubs on Friday
Answer:
(5.4582 ; 6.8618)
Step-by-step explanation:
Given the data:
6 10 2 6 3 3 3 6 6 6 6 5 8 9 10 10 7 9 3 6 5 10 9 9 10 3 8 6 6 3 3 6 6 5 4 10 9 3 5 7 10 6 3 8 6 8 3 3 5 5
Sample mean, xbar = Σx / n
n = sample size = 50
ΣX = 308
xbar = 308 / 50 = 6.16
Using a Calculator :
The sample standard deviation, s = 2.469
Confidence interval = xbar ± margin of error
Margin of Error = Tcritical * s/sqrt(n)
Tcritical at 95% ; df = 50 - 1 = 49
Tcritical = 2.010
Hence,
Margin of Error= 2.010 * (2.469/sqrt(50)) = 0.7018
Lower boundary : (6.16 - 0.7018) = 5.4582
Upper boundary : (6.16 + 0.7018) = 6.8618
(5.4582 ; 6.8618)
