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3 years ago

1. Evaluate the expression for 0.8 and z=3.5

Mathematics

1 answer:

puteri [66]3 years ago

8 0

Answer:

1. 4(.8)-3.5= 3.2-3.5= -0.3

2. 3(3)--5(5)-9(-1)= 9 - 25 + 9 = 18 - 25= -7

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Help pls (8grade math)

Gwar [14]

Answer:

I think it's G

Step-by-step explanation:

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5 0

3 years ago

A man buys a racehorse for $20,000 and enters it in two races. He plans to sell the horse afterward, hoping to make a profit. If

victus00 [196]

Answer:

The expected profit is $10,600.

Step-by-step explanation:

The expected profit can be calculated as the sum of the possible outcomes weighted by their probability of occurrence.

In this case, there are four possible outcomes:

1) The horse win both races. The value of the horse will be $100k-$20k=$80k.

The probability of this outcome is:

$P(ww)=P(w1)*P(w2)=0.2*0.3=0.06$

2) The horse win the first race, but lose the second one. The value will be $50k-$20k=$30k.

The probability is:

$P(wl)=P(w1)*(1-P(w2))=0.2*(1-0.3)=0.2*0.7=0.14$

3) The horse lose the first race, but win the second one. The value will be $50k-$20k=$30k.

The probability is:

$P(lw)=(1-P(w1))*P(w2)=(1-0.2)*0.3=0.8*0.3=0.24$

4) The horse lose both races. The value will be $10k-$20k=-$10k.

The probability is:

$P(lw)=(1-P(w1))*(1-P(w2))=(1-0.2)*(1-0.3)=0.8*0.7=0.56$

Then, the expected profit can be calculated as:

$E(x)=\sum\limits^4_{i=1} {p_ix_i}\\\\E(x)=0.06*80,000+0.14*30,000+0.24*30,000+0.56*(-10,000)\\\\E(x)=4,800+4.200+7,200-5,600=10,600$

6 0

3 years ago

Test the claim that the proportion of men who own cats is smaller than the proportion of women who own cats at the .10 significa

nata0808 [166]

Answer:

The test statistics is $t = -1.40$

The critical value is $Z_{\alpha } = 2.33$

The null hypothesis is rejected

Step-by-step explanation:

From the question we are told that

The sample size for men is $n_1 = 80$

The sample proportion of men that own a cat is $\r p _M = 0.40$

The sample size for women is $n_2 = 80$

The sample proportion of women that own a cat is $\r p_F = 0.51$

The level of significance is $\alpha = 0.10$

The null hypothesis is $H_o : \r p _M = \ r P_F$

The alternative hypothesis is $H_a : \r p _M < \r p_F$

Generally the test statistic is mathematically represented as

$t = \frac{(\r p_M - \r p_F)}{\sqrt{\frac{(p_M*(1-p_M)}{n_1 } } + \frac{p_F*(1-pF)}{n_2 } }$

=> $t = \frac{(0.40 - 0.51)}{\sqrt{\frac{(0.40 *(1-0.41)}{80} } + \frac{0.51*(1-0.51)}{80 } }$

=> $t = -1.40$

The critical value of $\alpha$ from the normal distribution table is

$Z_{\alpha } = 2.33$

The p-value is obtained from the z-table ,the value is

$p-value = P( Z < -1.40) = 0.080757$

=> $p-value = 0.080757$

Given that the $p-value < \alpha$ then we reject the null hypothesis

7 0

3 years ago

A school band raised $252 by holding a car wash. The band

Mrrafil [7]

Answer: See explanation

Step-by-step explanation:

From the question, we are informed that the school band raised $252 by holding a car wash and that the band

washed 42 cars in all.

The equation can be used to find n, the average amount they earned per car will be:

n = $252 / 42

n = $6

The amount earned per car is $6

7 0

3 years ago

For a normal population with a mean of m = 80 and a standard deviation of s = 10, what is the probability of obtaining a sample

igomit [66]

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5 0

3 years ago