Minato drove 390 miles. Part of the drive was along local roads, where his average speed was 20 mph, and the rest was along a hi
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Answer:
Step-by-step explanation:
My favorite way to go at this is to look at a graph. It shows the vertex at (-2, -11). Since the leading coefficient is 2, this means the roots are ...
where the 2 in the denominator of the radical is the leading coefficient.
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You can also use other clues:
- the axis of symmetry is -b/(2a) = -8/(2(2)) = -2, so answer choices C and D don't work
- the single change in sign in the coefficients (+ + -) tells you there is one positive real root, so answer choice B doesn't work.
The first answer choice is the only one with values symmetrical about -2 and one of them positive.
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You may be expected to use the quadratic formula:
Answer:
There is enough statistical evidence to support the claim that the survey is not accurate.
Step-by-step explanation:
We have to perform a test of hypothesis on the proportion.
The claim is that the proportion of families that own stock differs from 48.8%.
Then, the null and alternative hypothesis are:
The significance level is 0.05.
The sample. of size n=250, has a proportion of p=0.568.
The standard error of the proportion is
The z-statistic can now be calculated:
The P-value for this two-tailed test is then:
As the P-value is smaller than the significance level, the effect is significant. The null hypothesis is rejected.
There is enough evidence to support the claim that the survey is not accurate.
Bernard’s walking speed is 140 meters per minute
Bernard’s walking speed is 8.4 kilometers per hour
Step-by-step explanation:
The pace length P is the distance between the rear of two consecutive footprints
The formula, n P = 140, gives an approximate relationship between n and P where,
- n = number of steps per minute
- P = pace length in meters
- Bernard knows his pace length is 0.80 meters
- The formula applies to Bernard’s walking
We need to calculate Bernard’s walking speed in meters per minute and in kilometers per hour
∵ n = number of steps per minute
∴ n unit is number / minute
∵ P = pace length in meters
∴ P unit is meter
- That means n P unit is meters/minute
∴ n P represents the speed in meters per second
∵ The formula applies to Bernard’s walking
∵ His pace length is 0.80 meters
∵ n P = 140
∴ n(0.8) = 140
- Divide both sides by 0.8
∴ n = 175
- That means he moves 175 steps per minute
∵ The distance he walks in minute = 175 × 0.8 = 140 meters/minute
∴ His speed is 140 meters per minute
Bernard’s walking speed is 140 meters per minute
∵ 1 km = 1000 m
∵ 1 hour = 60 minutes
- Divide the meters by 1000 and the minute by 60 to change
from meters per minute to kilometers per hour
∴ His walking speed = ÷
- Change ÷ to × and reciprocal the fraction after the division sign
∴ His walking speed = ×
= 8.4 km/h
Bernard’s walking speed is 8.4 kilometers per hour
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You can learn more about the speed in brainly.com/question/5461619
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