Answer:
The probability that the sample proportion is between 0.35 and 0.5 is 0.7895
Step-by-step explanation:
To calculate the probability that the sample proportion is between 0.35 and 0.5 we need to know the z-scores of the sample proportions 0.35 and 0.5.
z-score of the sample proportion is calculated as
z=
where
- p(s) is the sample proportion of first time customers
- p is the proportion of first time customers based on historical data
For the sample proportion 0.35:
z(0.35)=
≈ -1.035
For the sample proportion 0.5:
z(0.5)=
≈ 1.553
The probabilities for z of being smaller than these z-scores are:
P(z<z(0.35))= 0.1503
P(z<z(0.5))= 0.9398
Then the probability that the sample proportion is between 0.35 and 0.5 is
P(z(0.35)<z<z(0.5))= 0.9398 - 0.1503 =0.7895
1 3/10·b=39
(1·10+3)·b/10=39
13b/10=39
13b=39·10
13b=390|:13
<u>b=30</u>
<em>Answer: 30</em>
About 3.8 hours, if asking for a whole number round to 4
Answer:
Step-by-step explanation:
2x⁴ + 4x³ - 30x² = 2x²*(x² + 2x - 15)
x² + 2x - 15
Sum = 2
Product = -15
Factors = 5 ; (-3)
x² + 2x - 15 = x² + 5x - 3x - 3 *5
= x(x + 5) - 3(x + 5)
= (x + 5)(x - 3)
2x⁴ + 4x³ - 30x² = (2x²) (x + 5)(x - 3)
20,21, and 29.
Use the Pythagorean Theorem to plug in all the options. 20²+21²=841. The square root of 841 is 29.