66 2/3% as a fraction in simplest form Show Work pls PS. ON PIC ITS #14

50 random teenagers were asked how many hours a day they use their phone. They spent an average of 7 hours a day with a standard

tatyana61 [14]

Answer:

The margin of error for the true mean number of hours a teenager spends on their phone is of 0.4 hours a day.

Step-by-step explanation:

We have the standard deviation of the saple, so we use the t-distribution to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 50 - 1 = 49

95% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 49 degrees of freedom(y-axis) and a confidence level of $1 - \frac{1 - 0.95}{2} = 0.975$ . So we have T = 2

The margin of error is:

$M = T\frac{s}{\sqrt{n}} = 2\frac{1.3}{\sqrt{50}} = 0.4$

In which s is the standard deviation of the sample and n is the size of the sample.

The margin of error for the true mean number of hours a teenager spends on their phone is of 0.4 hours a day.

4 0

2 years ago

I need help please with this math problem.

dezoksy [38]

Answer:

They are equal

Both answer is 65

Step-by-step explanation:

5x -30 = 2x +27

5x -2x = 27 +30

3x = 57

x = 57/3 = 19

5x -30 = 5(19) -30 = 65

2x +27 = 2(19) +27 = 65

5 0

2 years ago

Pls help. I’m so confused

dusya [7]

Answer:

25 units

Step-by-step explanation:

The longest side is 12.

The two other sides of the triangle = (3 sqaured + 6 squared) (9+36) the square root of 45 is about 6.7.

6.7 x 2 = 13.4

13.4 + 12 = 25.4

25.4 rounded to the nearest unit is 25

5 0

3 years ago

Read 2 more answers

100 POINTS + BRAINLIEST !!!!!!!!

spin [16.1K]

Answer: (i) 15% (ii) 0.6%

Step-by-step explanation:

Given: P(A) = 0.3 ⇒ ~P(A) = 0.7

P(B) = 0.3 ⇒ ~P(B) = 0.7

P(A ∪ B) = 0.6 ⇒ ~P(A ∪ B) = 0.4

If you don't have a calculator function for the Binomial Formula, the equation is: $P(X)=\dfrac{n!}{X!(n-X)!}\cdot p^X\cdot (1-p)^{n-X}$ where

n is the number of trials
p is the probability of success
X is the number of successes

(i) Probability of at least 5 --> P(X ≥ 5) means P(5) + P(6) + P(7) + P(8) + P(9) + P(10)

P(5): n = 10, p = 0.3, X = 5 → P(5) = 0.1029

P(6): n = 10, p = 0.3, X = 6 → P(6) = 0.0368

P(7): n = 10, p = 0.3, X = 7 → P(7) = 0.0090

P(8): n = 10, p = 0.3, X = 8 → P(8) = 0.0014

P(9): n = 10, p = 0.3, X = 9 → P(9) = 0.0001

P(10): n = 10, p = 0.3, X = 10 → P(10) = 0.0000

TOTAL = 0.1502 → 15.02%

(ii) Probability of A or B = 10 --> P(X = 10)

P(10): n = 10, p = 0.6, X = 10 → P(10) = 0.0060 → 0.6%

4 0

3 years ago

7.89 × 0.007 = 23.45 × 6.7 = 1.23 × .12 =

Romashka-Z-Leto [24]

7.89 × 0.007 = 0.05523

23.45 × 6.7 =157.155

1.23 x .12 = 0.156

6 0

3 years ago

Read 2 more answers

66 2/3% as a fraction in simplest formShow Work plsPS. ON PIC ITS #14