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2 years ago

7

if a student scored 78 points on a test where the mean score was 84.5 and the standard deviation was 3.1. the student's z score

is

1 answer:

son4ous [18]2 years ago

5 0

Answer:

(number - mean)/standard deviation.

Plug in the 78 for the number, the 84.5 for the mean, the 3.1 for the standard deviation.

Step-by-step explanation:

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Lindy works at a pizza restaurant and gets a 10% employee discount. She knows that if she orders d drinks and a medium pizza wit

timurjin [86]

Answer:

Option A. $17.28

Step-by-step explanation:

we have the expression for the cost

$0.90(2.25d+1.40t+6)$

In this problem we have

$d=4, t=3$

substitute the given values in the expression to obtain the cost

$0.90(2.25(4)+1.40(3)+6)=\$17.28$

5 0

2 years ago

Read 2 more answers

Use forward and backward difference approximations of O(h) and a centered difference approximation of O(h2) to estimate the firs

strojnjashka [21]

Answer:

Answer has explained below.

Step-by-step explanation:

Consider the function is:

F(x) = 25x3 – 6x2 +7x -88

Differentiate with respect to x, we get

F’(x) = 25. 3x2 – 6.2x + 7

= 75x2 – 12x +7

At x = 2, we have

F (2) = 25(2)3 – 6(2)2 + 7(2)-88

=102

And f’(2) = 75(2)2 – 12 (2) +7

=283

Now, calculate forward divided difference as:

xi + 1 = xi + h

=2 + 0.25

=2.25

F (xi + 1) = f (2.25) = 25 (2.25)3 – 6(2.25)2 +7(2.25) -88

=182.21

f’(2) = f(2.25) – f(2) / 0.25 = 182.21 – 102 / 0.25

= 320.84

Єt = 283 – 320.8 / 283 = -13.36%

Now calculate backward divided difference:

Xi-1 = xi –h = 2 – 0.25 = 1.75

F(xi-1)= f(1.8) = 25 . (1.8)3 -6 (1.8)2 + 7 (1.8) – 88

= 50.96

F’(2) = f(2) – f(1.8) / 0.25 = 102 – 50.96 / 0.25 = 204.16

Єt = 283 – 204.16 / 283 = 27.86%

Finally, centered divided difference is obtain by inserting f(xi+1) and f (xi-1):

F’(2) = f(2.25) – f(1.8) /2 x 0.25 = 320.84 -50.96 / 0.5 = 539.68

Єt = 283 – 539.68 / 283 = -90.7%

6 0

2 years ago

A lotion is made from an oil blend costing $1.50 per ounce and glycerin costing $1.00 per ounce. Four ounces of lotion costs $5.

Svet_ta [14]

Answer:

A (4-g)1.5

Step-by-step explanation:

hope this helps if you need a explanation just ask in the comments and I will.

8 0

2 years ago

A merry-go-round has a radius of 18 feet. If a passenger gets on a

bearhunter [10]

Answer:

The angle of rotation is 2.11 °

Step-by-step explanation:

Given as :

The radius of the round path = r = 18 feet

The length of the distance cover by wheel = l = 38 feet

Let The angle of rotation = Ф

Now, According to question

∵ length of the arc of a circle subtending an angle at center = Ф

So,

length of the distance cover by wheel = π × radius × $\frac{\Theta }{180^{\circ}}$

Since 180° = π radian

And π = 3.14

So, length of the distance cover by wheel = 180 °× radius × $\frac{\Theta }{180^{\circ}}$

i.e l = r × Ф

Or, Ф = $\frac{l}{r}$

Or, Ф = $\frac{38 feet}{18 feet}$

Or, Ф = 2.11 °

So, The angle of rotation = Ф = 2.11 °

Hence, The angle of rotation is 2.11 ° Answer

6 0

2 years ago

A landscape supply business charges $35 to deliver mulch. The cost of the mulch is $29.

Scorpion4ik [409]

Answer:

$209

Step-by-step explanation:

we know that

The equation of the line in slope intercept form is equal to

$y=mx+b$

where

m is the slope

b is the y-coordinate of the y-intercept (initial value)

Let

x ----> the volume of mulch in cubic yards

y ----> the total cost in dollars

we have that

The slope of the linear equation is

$m=29\ \frac{\$}{yd^3}$

$b=\$35$ ----> flat fee to deliver mulch

The linear equation is

$y=29x+35$

For x=6 yd^3

substitute in the equation and solve for y

$y=29(6)+35$

$y=\$209$

4 0

2 years ago