Answer:
ok
Step-by-step explanation:
Answer:
The probability that seven or more of them used their phones for guidance on purchasing decisions is 0.7886.
<em />
Step-by-step explanation:
<em>The question is incomplete:</em>
<em>What should I buy? A study conducted by a research group in a recent year reported that 57% of cell phone owners used their phones inside a store for guidance on purchasing decisions. A sample of 14 cell phone owners is studied. Round the answers to at least four decimal places. What is the probability that seven or more of them used their phones for guidance on purchasing decisions? </em>
We can model this as a binomial random variable, with p=0.57 and n=14.

a) We have to calculate the probability that seven or more of them used their phones for guidance on purchasing decisions:




Answer:
1⅚
Step-by-step explanation:
(3 + ⅔) ÷ 2
11/3 ÷ 2
11/3 × 1/2
11/6
1⅚
7₈/7₈, 2(-2) ˣ 2(-3), 4₂ ˣ 49-1), 5(-10)/5(-12)
25/3 ft/s is speed of the tip of his shadow moving when a man is 40 ft from the pole given that a street light is mounted at the top of a 15-ft-tall pole and the man is 6 ft tall who is walking away from the pole with a speed of 5 ft/s along a straight path. This can be obtained by considering this as a right angled triangle.
<h3>How fast is the tip of his shadow moving?</h3>
Let x be the length between man and the pole, y be the distance between the tip of the shadow and the pole.
Then y - x will be the length between the man and the tip of the shadow.
Since two triangles are similar, we can write

⇒15(y-x) = 6y
15 y - 15 x = 6y
9y = 15x
y = 15/9 x
y = 5/3 x
Differentiate both sides
dy/dt = 5/3 dx/dt
dy/dt is the speed of the tip of the shadow, dx/dt is the speed of the man.
Given that dx/dt = 5 ft/s
Thus dy/dt = (5/3)×5 ft/s
dy/dt = 25/3 ft/s
Hence 25/3 ft/s is speed of the tip of his shadow moving when a man is 40 ft from the pole given that a street light is mounted at the top of a 15-ft-tall pole and the man is 6 ft tall who is walking away from the pole with a speed of 5 ft/s along a straight path.
Learn more about similar triangles here:
brainly.com/question/8691470
#SPJ4