Solve the Problem $\chi ^ { 2 }$ Values Can Be Approximated as Follows

question 61

Multiple Choice

Solve the problem.
-For large numbers of degrees of freedom, the critical $\chi ^ { 2 }$ values can be approximated as follows:
$$\chi ^ { 2 } = \frac { 1 } { 2 } ( z + \sqrt { 2 k - 1 } ) ^ { 2 }$$
where $\mathrm { k }$ is the number of degrees of freedom and $\mathrm { z }$ is the critical value. To find the lower critical value, the negat z-value is used, to find the upper critical value, the positive z-value is used. Use this approximation to estimate the critical value of $\chi ^ { 2 }$ in a right-tailed hypothesis test with $\mathrm { n } = 125$ and $\alpha = 0.01$ .

• A) \(\chi ^ { 2 } \approx 167.285\)
• B) \(\chi ^ { 2 } \approx 163.981\)
• C) \(\chi ^ { 2 } \approx 168.448\)
• D) \(\chi ^ { 2 } \approx 162.833\)

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Definitions:

FET Switched Circuits

Electronic circuits where field-effect transistors (FETs) are used as switches to control electrical current flow.

Characteristic Impedance

A measure of how a conductor appears (regardless of length) to a high-frequency signal; for instance, a truck J1939 data backbone has a characteristic of 120 ohms. It cannot be measured with an ohmmeter.

J1939 Data Bus

A communication protocol based on CAN (Controller Area Network) used for the electronic control system of heavy-duty vehicles to transmit data and control information among various vehicle components.

Field Effect Transistor (FET)

An electronic relay switch of which there are two types: N-channel and P-channel. A gate (terminal) is used to alter channel status. Channel allows current to flow or not to flow from the source terminal to the drain terminal. Used on many current truck electronic systems because of their ability to allow a very small current to control a high current.