Write 2^60 as an exponent with a base of 8

A random sample of 250 students at a university finds that these students take a mean of 15.2 credit hours per quarter with a st

Orlov [11]

Answer:

95% confidence interval for the mean credit hours taken by a student each quarter is [14.915 hours , 15.485 hours].

Step-by-step explanation:

We are given that a random sample of 250 students at a university finds that these students take a mean of 15.2 credit hours per quarter with a standard deviation of 2.3 credit hours.

Firstly, the pivotal quantity for 95% 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 credit hours per quarter = 15.2 credit hours

s = sample standard deviation = 2.3 credit hours

n = sample of students = 250

$\mu$ = population mean credit hours per quarter

Here for constructing 95% confidence interval we have used One-sample t test statistics as we know don't about population standard deviation.

So, 95% confidence interval for the population mean, $\mu$ is ;

P(-1.96 < $t_2_4_9$ < 1.96) = 0.95 {As the critical value of t at 249 degree of

freedom are -1.96 & 1.96 with P = 2.5%}

P(-1.96 < $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ < 1.96) = 0.95

P( $-1.96 \times {\frac{s}{\sqrt{n} } }$ < ${\bar X-\mu}$ < $1.96 \times {\frac{s}{\sqrt{n} } }$ ) = 0.95

P( $\bar X-1.96 \times {\frac{s}{\sqrt{n} } }$ < $\mu$ < $\bar X+1.96 \times {\frac{s}{\sqrt{n} } }$ ) = 0.95

95% confidence interval for $\mu$ = [ $\bar X-1.96 \times {\frac{s}{\sqrt{n} } }$ , $\bar X+1.96 \times {\frac{s}{\sqrt{n} } }$ ]

= [ $15.2-1.96 \times {\frac{2.3}{\sqrt{250} } }$ , $15.2+1.96 \times {\frac{2.3}{\sqrt{250} } }$ ]

= [14.915 hours , 15.485 hours]

Therefore, 95% confidence interval for the mean credit hours taken by a student each quarter is [14.915 hours , 15.485 hours].

The interpretation of the above confidence interval is that we are 95% confident that the true mean credit hours taken by a student each quarter will be between 14.915 credit hours and 15.485 credit hours.

8 0

2 years ago

A 90% confidence interval for a population parameter means that if a large number of confidence intervals were constructed from

Elis [28]

Answer:

The correct option is a) True

Step-by-step explanation:

Consider the provided statement.

A 90% confidence interval for a population parameter means that if a large number of confidence intervals were constructed from repeated samples, then on average, 90% of these intervals would contain the true parameter

First understand what is 90% confidence interval.

The level of confidence describes the uncertainty associated with a method of sampling.

A confidence level of 90 percent means that we would expect the population parameter to be included in 90 percent of the interval estimates.

From the above definition of confidence level we can concluded that the provided statement is true.

Hence, The correct option is a) True

7 0

2 years ago

Use the diagram below to answer the questions.

garri49 [273]

answer:

Ray KM

Line JK

Ray MJ

4 0

2 years ago

Read 2 more answers

An experiment was done to look at the positive arousing effects of imagery on different people. A sample of statistics lecturers

statuscvo [17]

Answer:

The Three way mixed ANOVA

Step-by-step explanation:

The Three factor repeated measures ANOVA analysis otherwise referred to as the Three way mixed ANOVA should be used for the analysis.

This is because we are comparing three independent variables in the context.

• People type (statistic lectures and students)

• Imagery type (positive, neutral and negative imagery)

• Repeated measure: Before and After images shown

• Measuring the dependent variable positive arousal as shown in the table attached to the answer.

After going through the table attached you will see that there should be performed a three factor repeated measures ANOVA analysis.

5 0

2 years ago

Devon and his friends bought strawberry wafers for $3 per packet and chocolate wafers for $1 per packet at a carnival. They spen

Irina-Kira [14]

Hi there!

PART A:
The system of equations we would use would be:
x + y = 22 (amount of items)
3x + 1y = 30 (cost)

Variables:
x = the amount of strawberry wafers bought at the price of $3
y = the amount of chocolate wafers bought at the price of $1

PART B:
To solve, we'll use substitution because we can easily isolate a variable using the first equation.

Work:
x + y = 22 (first equation)
y = 22 - x (isolating a variable)
3x + 1y = 30 (second equation)
3x + (22 - x) = 30 (substituting into the second equation)
2x + 22 = 30 (simplifying)
2x = 8 (subtracting)
x = 4 strawberry wafers
4 + y = 22 (substituting x into the first equation to solve for y)
y = 18 chocolate wafers

ANSWER:
They bought 4 strawberry wafers and 18 chocolate wafers.

Hope this helps!! :)
If there's anything else that I can help you with, please let me know!

8 0

2 years ago