Answer:
0.8224
Step-by-step explanation:
Data
- standard deviation, sd: $10
- first value of interest, x1: $63
- second value of interest, x2: $90
z-score for x1:
z1 = (x1 - mean)/sd = (63 - 76)/10 = -1.3
z-score for x2:
z2 = (x2 - mean)/sd = (90 - 76)/10 = 1.4
The proportion of wrist watch prices are between $63 and $90 is:
P(z1 < z < z2) = P(z < 1.4) - P(z < -1.3)
P(z < 1.4) = 0.9192 (see first picture attached)
P(z < -1.3) = 0.0968 (see second picture attached)
P(z1 < z < z2) = 0.9192 - 0.0968 = 0.8224
Answer:
B
Step-by-step explanation:
4x + 6y = 28
-15x - 6y = -39
Answer:
7 ÷ 4/5 is 8.75 as a decimal or 8 3/4 as a fraction
Answer:
d is the correct answer from give questions
A quadratic equation is in the form of ax²+bx+c. The time at which the height of the ball is 16 feets is 0.717 seconds and 1.221 seconds.
<h3>What is a quadratic equation?</h3>
A quadratic equation is an equation whose leading coefficient is of second degree also the equation has only one unknown while it has 3 unknown numbers. It is written in the form of ax²+bx+c.
The complete question is:
A ball is thrown from an initial height of 2 feet with an initial upward velocity of 31 ft/s. The ball's height h (in feet) after 7 seconds is given by the following, h=2+31t-16t². Find all values of t for which the ball's height is 16 feet. Round your answer(s) to the nearest hundredth.
The time at which the height of the ball is 16 feet can be found by,
h = 2 + 31t - 16t²
16 = 2 + 31t - 16t²
16 - 2 - 31t + 16t² = 0
16t² - 31t + 14 = 0
t = 0.717 , 1.221
Hence, the time at which the height of the ball is 16 feets is 0.717 seconds and 1.221 seconds.
Learn more about Quadratic Equations:
brainly.com/question/2263981
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