Why did the football coach send in his second string

Assume the hold time of callers to a cable company is normally distributed with a mean of 5.5 minutes and a standard deviation o

Ierofanga [76]

Answer:

The percent of callers are 37.21 who are on hold.

Step-by-step explanation:

Given:

A normally distributed data.

Mean of the data, $\mu$ = 5.5 mins

Standard deviation, $\sigma$ = 0.4 mins

We have to find the callers percentage who are on hold between 5.4 and 5.8 mins.

Lets find z-score on each raw score.

⇒ $z_1=\frac{x_1-\mu}{\sigma}$ ...raw score, $x_1$ = $5.4$

⇒ Plugging the values.

⇒ $z_1=\frac{5.4-5.5}{0.4}$

⇒ $z_1=-0.25$

For raw score 5.5 the z score is.

⇒ $z_2=\frac{5.8-5.5}{0.4}$

⇒ $z_2=0.75$

Now we have to look upon the values from Z score table and arrange them in probability terms then convert it into percentages.

We have to work with P(5.4<z<5.8).

⇒ $P(5.4$

⇒ $P(-0.25$

⇒ $P(z$

⇒ $z(1.5)=0.7734$ and $z(-0.25)=0.4013$ ...from z -score table.

⇒ $0.7734-0.4013$

⇒ $0.3721$

To find the percentage we have to multiply with 100.

⇒ $0.3721\times 100$

⇒ $37.21$ %

The percent of callers who are on hold between 5.4 minutes to 5.8 minutes is 37.21

4 0

3 years ago

“7a - 17 = 4a +1” Step by step pls

Monica [59]

Answer:

a = 6

Step-by-step explanation:

7a-17 = 4a +1 ; Subtract 4a from both sides

3a - 17 = 1 ; Add 17 to both sides

3a = 18 ; Divide both sides by 3

a = 6

6 0

3 years ago

Read 2 more answers

Can someone please check this?

Naddik [55]

The first one in incorrect , it should be 130 but the rest are correct !

7 0

4 years ago

For which system of equations is (5, 3) the solution? A. 3x – 2y = 9 3x + 2y = 14 B. x – y = –2 4x – 3y = 11 C. –2x – y = –13 x

Alla [95]

The correct answer is:

D) $\left \{ {{2x-y=7} \atop {2x+7y=31}} \right.$ .

Explanation:

We solve each system to find the correct answer.

For A:
$\left \{ {{3x-2y=9} \atop {3x+2y=14}} \right.$

Since we have the coefficients of both variables the same, we will use elimination to solve this.

Since the coefficients of y are -2 and 2, we can add the equations to solve, since -2+2=0 and cancels the y variable:
$\left \{ {{3x-2y=9} \atop {+(3x+2y=14)}} \right. 
\\
\\6x=23$

Next we divide both sides by 6:
6x/6 = 23/6
x = 23/6

This is not the x-coordinate of the answer we are looking for, so A is not correct.

For B:
$\left \{ {{x-y=-2} \atop {4x-3y=11}} \right.$

For this equation, it will be easier to isolate a variable and use substitution, since the coefficient of both x and y in the first equation is 1:
x-y=-2

Add y to both sides:
x-y+y=-2+y
x=-2+y

We now substitute this in place of x in the second equation:
4x-3y=11
4(-2+y)-3y=11

Using the distributive property, we have:
4(-2)+4(y)-3y=11
-8+4y-3y=11

Combining like terms, we have:
-8+y=11

Add 8 to each side:
-8+y+8=11+8
y=19

This is not the y-coordinate of the answer we're looking for, so B is not correct.

For C:
Since the coefficient of x in the second equation is 1, we will use substitution again.

x+2y=-11

To isolate x, subtract 2y from each side:
x+2y-2y=-11-2y
x=-11-2y

Now substitute this in place of x in the first equation:
-2x-y=-13
-2(-11-2y)-y=-13

Using the distributive property, we have:
-2(-11)-2(-2y)-y=-13
22+4y-y=-13

Combining like terms:
22+3y=-13

Subtract 22 from each side:
22+3y-22=-13-22
3y=-35

Divide both sides by 3:
3y/3 = -35/3
y = -35/3

This is not the y-coordinate of the answer we're looking for, so C is not correct.

For D:
Since the coefficients of x are the same in each equation, we will use elimination. We have 2x in each equation; to eliminate this, we will subtract, since 2x-2x=0:

$\left \{ {{2x-y=7} \atop {-(2x+7y=31)}} \right. 
\\
\\-8y=-24$

Divide both sides by -8:
-8y/-8 = -24/-8
y=3

The y-coordinate is correct; next we check the x-coordinate Substitute the value for y into the first equation:
2x-y=7
2x-3=7

Add 3 to each side:
2x-3+3=7+3
2x=10

Divide each side by 2:
2x/2=10/2
x=5

This gives us the x- and y-coordinate we need, so D is the correct answer.

7 0

3 years ago

Tom bought a soft drink for $4.00 and 7 candy bars. He spent a total of $18.00. How

olga2289 [7]

Answer:

$2

Step-by-step explanation:

$18-$4=$14

$14/7=$2

8 0

3 years ago