In a class of 22 students, 15 play an instrument and 11 play a sport. There are 9

A student scored 66 points on his Psychology 101 midterm. If the average of his midterm and final must be between 78 and 90 incl

masha68 [24]

Answer:

range of scores on final exam student get B is 90 to 100

Step-by-step explanation:

given data

Psychology 101 score = 66

average of his midterm = between 78 and 90

maximum = 100 points

to find out

range of scores on final exam student get B

solution

we consider here lowest marks need in final = x

so average at two marks should be

equation is

average marks = 0.5 × ( mid term marks + final marks ) .................1

put here value

78 = 0.5 × ( 66 + x )

x = 90

and

90 = 0.5 × ( 66 + x )

x = 114

so range 90 to 114

but maximum marks is 100 so

range of scores on final exam student get B is 90 to 100

5 0

3 years ago

Each of the Space Shuttle's solid rocket motors burns 680,400 kilograms of propellant in 2.5 minutes. How much propellant does e

Likurg_2 [28]

Answer:

Step-by-step explanation:

6 0

3 years ago

Irene has 1 gallon of milk. She uses

Umnica [9.8K]

Answer:

32

Step-by-step explanation:

In 1 gallon, there are 128 ounces.

Divide 128 by 4 and get 32.

5 0

3 years ago

2x+1<9<br> I need help with this question

tia_tia [17]

Answer: x<4

Step-by-step explanation: Let's solve your inequality step-by-step.

2x+1<9

Step 1: Subtract 1 from both sides.

2x+1−1<9−1

2x < 8

Step 2: Divide both sides by 2.

2x /2 < 8 /2

x<4

4 0

3 years ago

The USDA conducted tests for salmonella in produce grown in California. In an independent sample of 252 cultures obtained from w

Marat540 [252]

Answer:

The decision rule is

Fail to reject the null hypothesis

The conclusion is

There no sufficient evidence to show that the proportion of salmonella in the region’s water differs from the proportion of salmonella in the region’s wildlife

Step-by-step explanation:

From the question we are told that

The first sample size is $n_1 = 252$

The number that tested positive is $k_1 = 18$

The second sample size is $n_2 = 476$

The number that tested positive is $k_2 = 20$

The level of significance is $\alpha = 0.01$

Generally the first sample proportion is mathematically represented as

$\^ p _1 = \frac{k_1 }{ n_1 }$

=> $\^ p _1 = \frac{18 }{ 252 }$

=> $\^ p _1 = 0.071$

Generally the second sample proportion is mathematically represented as

$\^ p _2 = \frac{k_2 }{ n_2 }$

=> $\^ p _2 = \frac{20 }{ 476}$

=> $\^ p _2 = 0.042$

The null hypothesis is $H_o : p_1 - p_2 = 0$

The alternative hypothesis is $H_a : p_1 - p_2 \ne 0$

Generally the test statistics is mathematically represented

$z = \frac{ \^ p_1 - \^ p_2 - ( p_ 1 - p_2 )}{ \sqrt{\frac{\^ p_1 (1-\^ p_1)}{ n_1 } + \frac{\^ p_2 (1-\^ p_2)}{ n_2 } } }$

=> $z = \frac{ 0.071 - 0.042 - 0 }{ \sqrt{\frac{0.071 (1-0.071)}{ 252 } + \frac{0.042 (1-\^ 0.042)}{ 476 } } }$

=> $z = 1.56$

From the z table the area under the normal curve to the right corresponding to 1.56 is

$P(Z > 1.56 ) =0.05938$

Generally the p-value is mathematically represented as

$p-value = 2 * P(Z > 1.56 )$

=> $p-value = 2 * 0.05938$

=> $p-value = 0.1188$

From the value obtained we see that $p-value > \alpha$ hence

The decision rule is

Fail to reject the null hypothesis

The conclusion is

There no sufficient evidence to show that the proportion of salmonella in the region’s water differs from the proportion of salmonella in the region’s wildlife

5 0

3 years ago