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2 years ago

Find the area under the standard normal curve between z=0.45 and z=1.13

Mathematics

1 answer:

Law Incorporation [45]2 years ago

8 0

Step-by-step explanation:

the answer is in the above image

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Lancer watched 6 videos. Each video was 33.5 minutes long. How long did Perla spend watching videos? A.6 minutes B.27.5 minutes

Mumz [18]

201 minutes because 6 multiplied by 33.5 = 201 minutes

5 0

3 years ago

The radius of a round tablecloth is 2.75 feet, how many yards is needed

kogti [31]

Answer:

Step-by-step explanation:

$A=\pi r^2\\ \\ A=\pi(2.75ft(yd/3ft))^2\\ \\ A\approx 2.64 yd^2$

5 0

2 years ago

Read 2 more answers

To study the output of a machine that fills boxes with cereal, a quality control engineer weighed 150 boxes of Brand X cereal. T

scoundrel [369]

Answer:

$\sigma = 0.07770$

Step-by-step explanation:

Given

The above table

Required

The standard deviation

First, calculate the class mid-point. This is the average of the class interval.

The mid-point x is:

$x_1 = \frac{1}{2}(15.3 + 15.6) =\frac{1}{2} * 30.9 = 15.45$

$x_2 = \frac{1}{2}(15.6 + 15.9) =\frac{1}{2} * 31.5 = 15.75$

$x_3 = \frac{1}{2}(15.9 + 16.2) =\frac{1}{2} * 32.1 = 16.05$

$x_4 = \frac{1}{2}(16.2 + 16.5) =\frac{1}{2} * 32.7 = 16.35$

$x_5 = \frac{1}{2}(16.5 + 16.8) =\frac{1}{2} * 33.3 = 16.65$

So, we have:

$\begin{array}{cccccc}x & {15.45} & {15.75} & {16.05} & {16.35} & {16.65} \ \\ f & {14} & {25} & {84} & {18} & {9} \ \end{array}$

Calculate mean

$\bar x = \frac{\sum fx}{\sum f}$

$\bar x = \frac{15.45 * 14 + 15.75 * 25 + 16.05 * 84 + 16.35 * 18 + 16.65 * 9}{14 + 25 + 84 + 18 + 9}$

$\bar x = \frac{2402.4}{150}$

$\bar x = 16.016$

The standard deviation is:

$\sigma = \sqrt{\frac{\sum(x_i - \bar x)^2}{\sum f}}$

$\sigma = \sqrt{\frac{(15.45 - 16.016)^2+ (15.75 - 16.016)^2+ (16.05 - 16.016)^2+ (16.35 - 16.016)^2+ (16.65 - 16.016)^2}{14 + 25 + 84 + 18 + 9}}$

$\sigma = \sqrt{\frac{0.90578}{150}}$

$\sigma = \sqrt{0.00603853333}$

$\sigma = 0.07770$

4 0

2 years ago

The function f is defined on the real numbers by f(x) = x + 2<br> What is the value of f(-3)?

kvasek [131]

Answer:

-1

Step-by-step explanation:

We can plug in -3 for x and solve:

f(-3) = -3 + 2

= -1

6 0

2 years ago

A ferris wheel with a 40-ft diameter rotates once every 30 seconds. the bottom of the wheel is located 1.5 feet above the ground

dmitriy555 [2]

Answer:

Step-by-step explanation:

Let y = -A cos B(t -c) + D

A, amplitude = 20ft

Period = 2π / B ( B = π / 15)

= 30

c = 0

Vertical shift D = 21.5 ft

Equation becomes

$y= -20 \cos \frac{\pi}{15}( t-0)+21.5$

$\to y=-20\cos \frac{\pi}{15} t+21.5$

a) Top of the ferris wheel is

t = 15sec, 45sec, height = 41.5ft

b) At the bottom of the ferris wheel

t = 0, 30sec, 60 sec

height = 1.5ft

c) Exact middle of the ferris wheel

t = 15/ 2 = 7.5sec, 22.5sec, 37.5sec, 52.5sec

d) $f(t) or h = -20 \cos (\frac{\pi}{15} t)+21.5$

3 0

2 years ago