Answer:
a: 0.8884
b: 0.9934
Step-by-step explanation:
We have µ = 300 and σ = 70. The sample size, n = 125.
For the sample to be within 8 units of the population mean, we would have sample values of 292 and 308, so we want to find:
P(292 < x < 308).
We need to find the z-scores that correspond to these values using the given data. See attached photo 1 for the calculation of these scores.
We have P(292 < x < 308) = 0.8884
Next we want the probability of the sample mean to be within 17 units of the population mean, so we want the values from 283 to 317. We want to find
P(283 < x < 317)
We need to find the z-scores that correspond to these values. See photo 2 for the calculation of these scores.
We have P(283 < x < 317) = 0.9934
Answer:
21
Step-by-step explanation:
1/3= 0.33
7/0.33
Your answer is B. 2
This is because to rationalise the denominator, we need to multiply it by (3 - √7), so we get:
(3 + √7)(3 - √7)
3 × 3 = 9
3 × √7 = 3√7
3 × -√7 = -3√7
√7 × -√7 = -7
So all in all you get 9 - 7 which is 2.
I hope this helps!
9514 1404 393
Answer:
(b) 15.32
Step-by-step explanation:
You can use your triangle sense to answer this.
The side x will always be shorter than the hypotenuse, 20. This eliminates the last two choices.
If the angle is 45°, then the sides are equal at about 0.707 times the length of the hypotenuse. That would make them 0.707×20 = 14.14. Since the angle is greater than 45°, the opposite side will be greater than 14.14. Only one answer choice fits between 14 and 20: the second choice -- 15.32.
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The mnemonic SOH CAH TOA reminds you of the relation ...
Sin = Opposite/Hypotenuse
sin(50°) = x/20
x = 20×sin(50°) . . . . multiply by 20 to find x
x ≈ 15.32 . . . . . . . . . use your calculator to evaluate
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The attachment is intended to show how the triangle side lengths change with angle.
