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3 years ago

The scoring of modern IQ tests is such that IQs have a Normal distribution with mean

Mathematics

1 answer:

Readme [11.4K]3 years ago

4 0

Answer:

114

Step-by-step explanation:

z = (x − μ) / σ

0.93 = (x − 100) / 15

x ≈ 114

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Explain how you would find 45 x 7/9 mentally

Artemon [7]

45*7/9

cross out 45 and 9

divide by 9

45/9=5

9/9=1

5*1*7

=587

=35

answer:

8 0

3 years ago

In October 2012, Apple introduced a much smaller variant of the Apple iPad, known as the iPad Mini. Weighing less than 11 ounces

nadya68 [22]

Answer:

a) 0.4286 = 42.86% probability that the battery life for an iPad Mini will be 10 hours or less

b) 0.2857 = 28.57% probability that the battery life for an iPad Mini will be at least 11 hours

c) 0.5714 = 57.14% probability that the battery life for an iPad Mini will be between 9.5 and 11.5 hours

d) 86 should have a battery life of at least 9 hours.

Step-by-step explanation:

An uniform probability is a case of probability in which each outcome is equally as likely.

For this situation, we have a lower limit of the distribution that we call a and an upper limit that we call b.

The probability that we find a value X lower than x is given by the following formula.

$P(X \leq x) = \frac{x - a}{b-a}$

The probability of being higher than x is:

$P(X > x) = \frac{b - x}{b-a}$

The probability of being between c and d is:

$P(c \leq X \leq d) = \frac{d-c}{b-a}$

Assume that battery life of the iPad Mini is uniformly distributed between 8.5 and 12 hours.

This means that $a = 8.5, b = 12$

a. What is the probability that the battery life for an iPad Mini will be 10 hours or less (to 4 decimals)?

$P(X \leq x) = \frac{x - a}{b-a}$

$P(X \leq 10) = \frac{10 - 8.5}{12 - 8.5} = 0.4286$

0.4286 = 42.86% probability that the battery life for an iPad Mini will be 10 hours or less.

b. What is the probability that the battery life for an iPad Mini will be at least 11 hours (to 4 decimals)?

$P(X > x) = \frac{b - x}{b-a}$

$P(X > 11) = \frac{12 - 11}{12 - 8.5} = 0.2857$

0.2857 = 28.57% probability that the battery life for an iPad Mini will be at least 11 hours

c. What is the probability that the battery life for an iPad Mini will be between 9.5 and 11.5 hours (to 4 decimals)?

$P(c \leq X \leq d) = \frac{d-c}{b-a}$

$P(9.5 \leq X \leq 11.5) = \frac{11.5 - 9.5}{12 - 8.5} = 0.5714$

0.5714 = 57.14% probability that the battery life for an iPad Mini will be between 9.5 and 11.5 hours.

d. In a shipment of 100 iPad Minis, how many should have a battery life of at least 9 hours (to nearest whole value)?

Proportion of iPad Minis with a battery life of at least 9 hours.

$P(X > 11) = \frac{12 - 9}{12 - 8.5} = 0.8571$

Out of 100:

0.8571*100 = 85.71

To the nearest whole number

86 should have a battery life of at least 9 hours.

5 0

3 years ago

Worth 10 points pls help

Olenka [21]

What subject is this

3 0

2 years ago

Use the intermediate value theorem to choose an interval over which the function, f(x)=2x^3 - 3x +5 is guaranteed to have a zero

Sergio039 [100]

Answer:

The answer is c. {0,2).

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

Solve the equation

inysia [295]

Answer:

x ≈ 1.32, x ≈ - 5.32

Step-by-step explanation:

Given

x² + 4x - 7 = 0 ( add 7 to both sides )

x² + 4x = 7

To complete the square

add ( half the coefficient of the x- term )² to both sides

x² + 2(2)x + 4 = 7 + 4

(x + 2)² = 11 ( take the square root of both sides )

x + 2 = ± $\sqrt11}$ ( subtract 2 from both sides )

x = - 2 ± $\sqrt{11}$

Thus

x = - 2 - $\sqrt{11}$ ≈ - 5.32 ( to 2 dec. places )

x = - 2 + $\sqrt{11}$ ≈ 1.32 ( to 2 dec. places )

8 0

3 years ago

Read 2 more answers