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3 years ago

5

Jeremy wants to buy a backpack that costs $65. Luckily, the store is having a 35% off sale. What will be the sale price of the b

ackpack?

1 answer:

Leya [2.2K]3 years ago

7 0

Answer:

42.25

Step-by-step explanation:

65*35%=22.75

65-22.75=42.25

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What is 2 exponent 4 time 2 exponent negative 7 equal

Elena L [17]

Answer: i’m not sure if it’s just simplifying or factoring. but for simplifying it equals. 1/8 or .125

Explanation: calculator

4 0

3 years ago

A random sample of 10 parking meters in a resort community showed the following incomes for a day. Assume the incomes are normal

GenaCL600 [577]

Answer:

A 95% confidence interval for the true mean is [$3.39, $6.01].

Step-by-step explanation:

We are given that a random sample of 10 parking meters in a resort community showed the following incomes for a day;

Incomes (X): $3.60, $4.50, $2.80, $6.30, $2.60, $5.20, $6.75, $4.25, $8.00, $3.00.

Firstly, the pivotal quantity for finding the confidence interval for the population mean is given by;

P.Q. = $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ ~ $t_n_-_1$

where, $\bar X$ = sample mean income = $\frac{\sum X}{n}$ = $4.70

s = sample standard deviation = $\sqrt{\frac{\sum (X-\bar X)^{2} }{n-1} }$ = $1.83

n = sample of parking meters = 10

$\mu$ = population mean

<em>Here for constructing a 95% confidence interval we have used a One-sample t-test statistics because we don't know about population standard deviation.</em>

<u>So, 95% confidence interval for the population mean, </u> $\mu$ <u> is ;</u>

P(-2.262 < $t_9$ < 2.262) = 0.95 {As the critical value of t at 9 degrees of

freedom are -2.262 & 2.262 with P = 2.5%}

P(-2.262 < $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ < 2.262) = 0.95

P( $-2.262 \times {\frac{s}{\sqrt{n} } }$ < ${\bar X-\mu$ < $2.262 \times {\frac{s}{\sqrt{n} } }$ ) = 0.95

P( $\bar X-2.262 \times {\frac{s}{\sqrt{n} } }$ < $\mu$ < $\bar X+2.262 \times {\frac{s}{\sqrt{n} } }$ ) = 0.95

<u>95% confidence interval for</u> $\mu$ = [ $\bar X-2.262 \times {\frac{s}{\sqrt{n} } }$ , $\bar X+2.262 \times {\frac{s}{\sqrt{n} } }$ ]

= [ $4.70-2.262 \times {\frac{1.83}{\sqrt{10} } }$ , $4.70+ 2.262 \times {\frac{1.83}{\sqrt{10} } }$ ]

= [$3.39, $6.01]

Therefore, a 95% confidence interval for the true mean is [$3.39, $6.01].

The interpretation of the above result is that we are 95% confident that the true mean will lie between incomes of $3.39 and $6.01.

Also, the margin of error = $2.262 \times {\frac{s}{\sqrt{n} } }$

= $2.262 \times {\frac{1.83}{\sqrt{10} } }$ = <u>1.31</u>

4 0

3 years ago

You buy books for 64 cents each, you plan to sell them for 75 cents each. You're left with 100 unsold books, and you lost $12. H

PSYCHO15rus [73]

The number of books sold is 473.

<u>Step-by-step explanation:</u>

The original cost of each book = $0.64
The selling price of each book = $0.75

The difference between the original price and selling price of the book gives the profit per book.

The profit of one book = Selling price - Original price

Let,

The total number of books be 'x'.
The number of books sold be 'y'.
The unsold books is 100.
The total profit is -12 because it was gone to a loss of $12.

Therefore, the equation is formed as

total Profit = 0.75y - 0.64x

⇒ 0.75y - 0.64x = -12 --------(1)

Total books = sold books + unsold books

x = y + 100

⇒ x-y = 100 -------(2)

Substitute x= 100+y in the eq(1),

0.75y - 0.64(100+y) = -12

0.75y - 64 -0.64y = -12

0.11y = -12 +64

y = 52 / 0.11

y = 472.7

y ≅ 473

The number of book sold is 473 books.

The total number of books is (100+473) = 573 books.

8 0

3 years ago

There are two drama classesoffered at a middle school. The 8th grade class has 13 fewer students than the 7th grade class. If th

Eddi Din [679]

Answer:

Class 8 has 27 and class 7 has 40

Step-by-step explanation:

8th (r) class has 13 fewer than 7th (x).
x -13 = r

Total for both classes = 67

r + x - 13 = 67
r + x = 80

80 divided by two = 40 (per class)

40 - 13 = 27

4 0

2 years ago

A new car that costs $17,500 loses 25 percent of its value in the first year. How much is the loss of the value.

EastWind [94]

$\bf \begin{array}{|c|ll} \cline{1-1} \textit{a\% of b}\\ \cline{1-1} \\ \left( \cfrac{a}{100} \right)\cdot b \\\\ \cline{1-1} \end{array}~\hspace{5em}\stackrel{\textit{25\% of 17500}}{\left( \cfrac{25}{100} \right)17500}\implies 4375$

4 0

3 years ago