Answer:
Null hypothesis is rejected. Standard deviation is > 8 miles per hour
Step-by-step explanation:
σ [Population standard deviation] = 8 , s [sample standard deviation] = s
n [no of items] = 8
H0 [Null] : σ = 8 ; H1 [Alternate - Right Tail] : σ > 8
χ2 = (n - 1) . s^2 / σ^2
= 49 x (10.5)^2 / 82 = 5402.25 / 64
χ2 = 84.410
df [degree of freedom] = n -1 = 50 - 1 = 49
P value (χ^2 49 > 84.410) = 0.00125
p = 0.0013
p < α ie 0.05
So, H0 is rejected
Hence we state that standard deviation is > 8 miles per hpur
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Answer:
For Q. 17 I believe it's "the function has a minimum at -1" take this answer with a grain of salt but the other three seem to be true and I don't know how to solve this one so I'm assuming it's the false one.
Answer:
The highest score is 94.
Step-by-step explanation:
Let the highest score be denoted by, <em>A</em>, the lowest score be, <em>B</em> and the middle score be <em>X</em>.
Then,
A + X + B = 87 × 3 = 261 ...(i)
X + B = 83.5 × 2 = 167 ...(ii)
⇒ B = 167 - X ...(iii)
A + X = 89 × 2 = 178 ...(iv)
⇒ A = 178 - X ...(v)
Substitute (iii) and (v) in (i) and solve for <em>X</em> as follows:
A + X + B = 261
178 - X + X + 167 - X = 261
345 - X = 261
X = 84
Substitute the value of <em>X</em> in (iii) and solve for B as follows:
B = 167 - X
= 167 - 84
= 83
Substitute the value of <em>X</em> in (v) and solve for A as follows:
A = 178 - X
= 178 - 84
= 94
Thus, the highest score is 94.
