All categories

2 years ago

When Jennifer spent 3/7 of her money, she has $72 left. How much money did Jennifer start with?

1 answer:

3 0

After spending 3/7, she is left with;
4/7
Now, 4/7 is equivalent to 72
7/7 is equivalent to?
$\frac{7*72}{4}$
= 126 dollars

You might be interested in

Julia is offered a job selling advertising for two different companies. Company A offers a base salary of $30,000 per year plus

patriot [66]

A=30000+0.03S and B=25000+0.05S.
When A=B, 5000=0.02S, so S=$250000 when the earnings are the same.
The slope of A is smaller than that of B. In excess of this value of S B pays more than A and below it A pays more than B.
So answer option B. (When S=0, clearly A is better than B. Put S=$300000, A pays $39000 and B pays $40000).

8 0

1 year ago

Read 2 more answers

Karson drove from his house to work at an average speed of 35 miles per hour. The drive took him 20 minutes. If the drive took

Nastasia [14]

Answer:

Karson's average speed on his way home was 28 miles per hour.

Step-by-step explanation:

Since Karson drove from his house to work at an average speed of 35 miles per hour, and the drive took him 20 minutes, if the drive took him 25 minutes and he used the same route in reverse, to determine what was his average speed going home, the following calculation must be performed:

60 = 35

20 = X

20 x 35/60 = X

700/60 = X

11.666 = X

25 = 11,666

60 = X

60 x 11.666 / 25 = X

27.99 = X

Therefore, Karson's average speed on his way home was 28 miles per hour.

3 0

1 year ago

Margaret and Bethany have a lemonade stand for one week each summer.

Monica [59]

Answer:

6.00

Step-by-step explanation:

5 0

1 year ago

What weight of dry substance is in 150g of a 3% substance solution? What weight of an 8% solution can we have with the same weig

Pavlova-9 [17]

The answers are: 4.5 g and 56.25 g respectively.

Since the first type of measurement in this question is weight or mass, I'll suppose that the percentage concentration is % mass/mass. For that type of concentration measurement, just multiply the percentage by the total mass to get the mass of the wanted material.
So 150 g * 3% = 150 g * 0.03 = 4.5g

For the 8% solution with the same amount of dry substance, use the ratio of percentages, multiplied by the mass of the first solution to get the wanted amount of new solution:
3/8 * 150 g = 56.35 g

5 0

1 year ago

A company produces precision 1 meter (1000 mm) rulers. the actual distribution of lengths of the rulers produced by this company

pogonyaev

Let X be the length of rulers. X follows Normal distribution with mean μ and standard deviation σ = 0.02. A sample of size n=4 is drawn from population and sample mean m=1000. We have to find 90% confidence interval for population mean μ.

Here population standard deviation is given to us so we will use z confidence interval for mean. It is given as

(Sample mean - Margin of error , Sample mean + Margin of error)

Where margin of error for z confidence interval is

ME = σ $\frac{z_{\alpha/2}}{\sqrt{n}}$

Where σ = population standard deviation = 0.02

n= sample size =4

$z_{\alpha/2}$ = Critical z score value for given confidence level

We have to find here 90% confidence interval so confidence level c= 0.9

α = 1 -c =1-0.9 = 0.1

$z_{\alpha/2}$ = $z_{0.1/2}$ = $z_{0.05}$

Here we have to find z score value such that area below it is -z is 0.05 and above z is 0.05

Using excel function to find z score value

=NORM.S.INV(0.05) = -1.645

For calculating confidence interval we consider positive z score value which is 1.645

So the margin of error is

ME = $\frac{0.02 * 1.645}{\sqrt{4}}$

ME = 0.01645

90% confidence interval for mean is

(Sample mean - ME, Sample mean+ME)

1000- 0.01645, 1000+0.01645

(1000.01645, 999.9836)

Rounding interval upto 3 decimal places

(1000.016, 999.984)

90% confidence interval for population mean is (1000.016, 999.984)

7 0

1 year ago