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2 years ago

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Martin is saving for a gaming system. The total cost of the gaming system and three games is $325.49. About how much money shoul

d he save per week to puchased the gaming system and games in 20 weeks?

1 answer:

cestrela7 [59]2 years ago

4 0

First you would do $325.49 divided by 20 and you would get $16.27. so you would need $16.27 a week.

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Suppose that 20% of the adult women in the United States dye or highlight their hair. We would like to know the probability that

Rasek [7]

Answer:

71.08% probability that pˆ takes a value between 0.17 and 0.23.

Step-by-step explanation:

We use the binomial approxiation to the normal to solve this question.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

Normal probability distribution

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

When we are approximating a binomial distribution to a normal one, we have that $\mu = E(X)$ , $\sigma = \sqrt{V(X)}$ .

In this problem, we have that:

$p = 0.2, n = 200$ . So

$\mu = E(X) = np = 200*0.2 = 40$

$\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{200*0.2*0.8} = 5.66$

In other words, find probability that pˆ takes a value between 0.17 and 0.23.

This probability is the pvalue of Z when X = 200*0.23 = 46 subtracted by the pvalue of Z when X = 200*0.17 = 34. So

X = 46

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{46 - 40}{5.66}$

$Z = 1.06$

$Z = 1.06$ has a pvalue of 0.8554

X = 34

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{34 - 40}{5.66}$

$Z = -1.06$

$Z = -1.06$ has a pvalue of 0.1446

0.8554 - 0.1446 = 0.7108

71.08% probability that pˆ takes a value between 0.17 and 0.23.

6 0

2 years ago

Triangle A B C is reflected across line m to form triangle A prime B prime C prime. Triangle A prime B prime C prime is rotated

Helga [31]

Answer:

reflection across line m
rotation about point A'

Step-by-step explanation:

The problem statement tells you exactly what the transformations are.

The first transformation is reflection across line m.

The second transformation is rotation about point A'.

_____

These are both rigid transformations, so ΔABC ≅ A'B''C''.

6 0

2 years ago

There are 20 children in the cast of a class play, and 8 of the children are boys. of the boys, 4 have a speaking part in the pl

likoan [24]

The probability that a child with a speaking part is chosen randomly would be 2:5.

6 0

2 years ago

Workers have packed 1,400 glasses in 7 boxes. If they pack 3 more boxes, how many glasses will they have packed in all?

Alexandra [31]

2000

1box = 1400/7 = 200
200×3=600
1400+600=2000

Step-by-step explanation:
Given :Workers have packed 1,400 glasses in 7 boxes.
To Find :If they pack 3 more boxes, how many glasses will they have packed in all?
Solution:
Workers packed no. of glasses in 7 boxes = 1400
Workers packed no. of glasses in 1 box =
Workers packed no. of glasses in 3 boxes =
=
So, initially they packed 1400 glasses
If they pack 3 more boxes so, the pack 600 glasses more
So, The total no. of glasses have packed by workers = 1400+600 = 2000
Hence they have packed 2000 glasses in all.

5 0

2 years ago

e-lub [12.9K]

Divide the APR by 360 days and multiply it by 30 days to get the monthly interest. Each loan is usually secured by the car you bought. So we will use the secured APR.

8. Average rating secured apr: 5.85% divide by 360 multiply by 30: 0.4875% monthly rate
Cost of car: 19,725 ; sales tax: 4.75% ; down payment: 2,175

19,725 x 1.0475 = 20,661.94 - 2,175 = 18,486.94 loan amount
18,486.94 x 0.4875% = 90.12 accrued interest for the 1st month.

9. Excellent rating secured apr: 4.80% divide by 360 multiply by 30: 0.40% monthly rate
Cost of car: 15,867 ; sales tax: 5.25% ; down payment: 10% of total cost

15,867 x 1.0525 = 16,700.02 x 90% = 15,030.02 the principal balance at the start of the loan.

10. Fair rating secured apr: 7% divide by 360 multiply by 30: 0.5833% monthly rate
Cost of new car: 19,072 ; sales tax: 4.5% ; down payment: 1,200
Cost of used car: 15,365; sales tax: 4.5% ; down payment: 1,200

19,072 x 1.045 = 19,930.24 - 1,200 = 18,730.24
18,730.24 x 0.5833% = 109.25 accrued interest

15,365 x 1.045 = 16,056.43 - 1,200 = 14,856.43
14,856.43 x 0.5833% = 86.66 accrued interest

109.25 - 86.66 = 22.59 is the difference in interest accrued by the end of the first month.

7 0

2 years ago